If you're pregnant (or trying to be), you'll quickly notice that the world of maternity care has its own unique language. Some of it's clinical, some of it's old-fashioned, and some of it's just plain confusing.
That's why we created this comprehensive glossary: to help you make sense of the terms you'll encounter during pregnancy, labor, birth, and the early postpartum period. Whether you're reading your ultrasound report or trying to understand a symptom, consider this your go-to guide for quick, trustworthy explanations.
You may also want to check out our list of community discussion acronyms, a guide to all the lingo you might run across.
A
Abdomen: The area of your body below the chest that holds the stomach, intestines, liver, and other organs. While the uterus is located in the lowest part of the abdomen (the pelvis), it pushes up as far as the chest as it expands throughout pregnancy.
Abortion: The loss of a pregnancy before 20 weeks. This may happen spontaneously (a miscarriage) or be medically induced (a planned termination). After 20 weeks, a pregnancy loss is called a stillbirth or intrauterine fetal demise.
Abruption: When the placenta begins to separate from uterine wall before the baby is born. Abruption usually causes vaginal bleeding and abdominal pain and requires prompt medical attention.
Abscess: A pus-filled cavity. A breast abscess can result from untreated mastitis, or breast infection. Symptoms of an abscess include throbbing pain, swelling, tenderness, localized heat, and fever. Treatment includes antibiotics and sometimes drainage.
Active labor: Part of the first stage of labor when your cervix dilates from about 6 to 10 centimeters. Active labor lasts an average of four to 10 hours. Contractions become stronger, longer (40 to 60 seconds), and closer together — about every three to four minutes.
Acupressure: A form of complementary and alternative medicine (CAM) that has roots in ancient Chinese medicine. It uses pressure from the fingers to heal and soothe aches and pains. During pregnancy, acupressure may help ease morning sickness, labor pain, and back pain.
Acupuncture: A form of complementary medicine that uses very thin needles placed at specific points on the body to help relieve pain and promote balance. Some pregnant women use acupuncture to combat morning sickness, labor pains, and back pains.
Afterbirth: The placenta and membranes that are delivered during the third stage of labor, after your baby is born.
Afterpains: A normal postpartum symptom, this cramping is triggered by the contractions of the uterus as it shrinks and makes its normal descent back into the pelvis. Afterpains are especially common during breastfeeding.
Alexander technique: A childbirth method that focuses on posture and movement. Some educators use it to help pregnant women reduce muscle tension and cope with labor pain.
Alpha-fetoprotein (AFP): A protein made by the fetus. AFP can be measured in your blood — most accurately between weeks 15 and 18 of pregnancy.
Alpha-fetoprotein test: A screening blood test done between 15 and 18 weeks of pregnancy. High AFP levels may signal a higher chance of neural tube defects like spina bifida, while low levels may be associated with Down syndrome. The test helps determine whether further testing, such as amniocentesis, might be recommended.
Alveoli: Tiny milk-producing sacs that are arranged in clusters throughout the breast. Each breast has hundreds of alveoli, which release milk into ducts that carry it to the nipple.
Amenorrhea: Absence of menstrual periods.
Amniocentesis: A diagnostic test usually done between 15 and 20 weeks of pregnancy (most often between 16 and 18 weeks). Amniocentesis tests the fluid inside the amniotic sac that surrounds the baby. The fluid, which contains the baby's skin cells, is drawn from the uterus through a hollow needle inserted through mom's abdominal wall. The sample is tested for chromosomal conditions, genetic disorders, and other fetal health concerns.
Amnioinfusion: Injection of a sterile saline solution into the amniotic sac. This might be done when there isn't enough amniotic fluid or when there's thick meconium staining.
Amniotic fluid: The clear, protective liquid inside the amniotic sac that surrounds your baby. It cushions your little one, maintains temperature, protects against infection, and helps the lungs develop. Your body continually replenishes it during pregnancy.
Amniotic sac: The thin membrane (also called the “bag of waters”) that surrounds your baby and holds the amniotic fluid. The amniotic sac or membranes will rupture naturally or be ruptured artificially during labor.
Amniotomy: Rupturing of the membranes (amniotic sac) by a doctor or midwife to help jump-start labor or speed labor that has slowed. Amniotomy is done with an instrument that looks like a long crochet hook with a sharp tip.
Anal fissures: Small tears in the anus that can cause pain or bleeding. Constipation is a common culprit, and hemorrhoids may occur at the same time.
Analgesia: Any method or medication that reduces the sensation of pain.
Analgesic: A medication that reduces the sensation of pain without loss of consciousness. Demerol is a commonly used analgesic during labor.
Anemia: A decrease in the number of red blood cells, usually due to a shortage of iron. Detected through a blood test, anemiacauses symptoms such as fatigue, weakness, breathlessness, or fainting spells. Eating a diet rich in iron and taking an iron supplement during the second half of pregnancy is crucial to keep up with the increased need for red blood cells.
Anencephaly: A rare and severe neural tube birth defect in which the baby has a malformed skull and little or no brain.
Anesthesia: A general term describing techniques to ease pain. Types of anesthesia often used during childbirth include local anesthesia, general anesthesia, and epidurals.
Anesthetic: A medication that produces partial or total loss of sensation.
Antenatal: Occurring or formed before birth. Another word for prenatal.
Antepartum: Occurring before childbirth, referring to the mother.
Aorta: The main artery that brings blood from the heart to the rest of the body. Lying flat on your back late in pregnancy can compress the aorta and reduce blood flow.
Apgar score: Your baby's first quick checkup, done at one minute and five minutes after birth. The Apgar test rates heart rate, breathing, muscle tone, reflexes, and skin color. A perfect Apgar score is 10. Typical scores are seven, eight, or nine.
Apnea: A brief pause in breathing during sleep, temporarily reducing the amount of oxygen that's taken in. Apnea is a common pregnancy sleep problem.
Areola: The dark area on the breast surrounding the nipple. During pregnancy, the areola can spread and darken. Whenbreastfeeding, the baby latches onto the areola — not just the nipple — to draw out milk.
Aromatherapy: The use of essential oils for relaxation or relief of discomfort. Because some oils can be too strong during pregnancy, it's best to use aromatherapy cautiously and under expert guidance.
Artificial insemination (AI): A fertility treatment in which sperm is inserted directly into the uterus using a small catheter. Also called intrauterine insemination (IUI).
Aspiration: Suctioning fluid or mucus from the airways. After birth, a provider may gently clear a newborn's mouth and nose to help with breathing and remove any meconium.
Assisted reproductive technology: Any medical procedure performed to help a woman become pregnant. See in vitro fertilization, artificial insemination, and gamete intra-fallopian transfer.
Augmentation of labor: Helping a naturally started labor progress more effectively. During augmentation, Pitocin (a synthetic form of the hormone oxytocin) is often used to make contractions stronger. Your practitioner may also rupture your membranes if your amniotic sac is still intact.
Autologous transfusion: A blood transfusion using your own blood, often donated ahead of time in anticipation of surgery.
AZT: An antiretroviral drug that may be used to treat an HIV-positive pregnant woman. See Retrovir, zidovudine.
B
Baby blues: A mild, short-term emotional dip that many new moms experience after birth. It's usually linked to big hormonal shifts plus the natural letdown after the excitement of delivery. Up to 60 to 80% of new moms feel the baby blues. (If feelings become intense or last longer than two weeks, it may be postpartum depression.)
Back labor: Intense back pain during labor. Back labor often happens when the baby is in the occiput posterior position — meaning the back of his head is pressing against your spine.
Bacterial vaginosis: A vaginal infection caused by an imbalance of bacteria. It can increase the risk of pregnancy complications like premature rupture of membranes or infection of the amniotic fluid. Antibiotics usually clear it up.
Bag of waters: See amniotic sac.
Basal body temperature (BBT): The body's temperature first thing in the morning. Tracking your basal body temperature(using a highly sensitive basal body thermometer) can help identify ovulation, since your temperature rises slightly around that time.
Belly sling: A supportive band worn under the belly during pregnancy. It helps take pressure off the lower back and may also ease groin or sciatic pain. Some belly slings come with hot/cold packs for extra comfort.
Biofeedback: A technique that teaches you to recognize and control certain body responses — like heart rate, breathing, or muscle tension. In pregnancy, biofeedback may help relieve headaches, insomnia, or even morning sickness.
Biophysical profile (BPP): An ultrasound-based test that looks at a baby's breathing movements, body movements, muscle tone, and amniotic fluid level. The biophysical profile is typically performed after week 32 of pregnancy, though it can be done earlier, after week 24.
Birth assistant: Someone trained to provide basic labor support during childbirth. A birth assistant helps comfort and support the laboring parent.
Birth canal: The pathway your baby travels through during birth. It includes the cervix, vagina, and vulva.
Birth defect: An abnormality that develops while a baby is forming in the uterus. Some birth defects are genetic, while others occur for unknown reasons.
Birthing ball: A large, inflatable ball (similar to an exercise ball) that you can sit or lean on during labor. Rocking or gently bouncing on the birthing ball may help you relax and can ease back discomfort during contractions.
Birthing center: A facility offering a home-like setting for childbirth. Designed for women with low-risk pregnancies, it may be a freestanding facility or located inside or near a hospital. Birthing centers often offer a more flexible environment than hospitals.
Birthing chair: A chair designed to support a laboring woman in a sitting or squatting position during delivery, allowing gravity to help with the baby's descent.
Birth plan: A written list of your labor and delivery preferences — like whether you'd like to move around during labor, your thoughts on induction or pain relief, or your wishes about photography. Share your birth plan with your provider, birth assistant, and labor nurses.
“It's good for everyone around you to know what you've decided and to abide by it,” says What to Expect Community mom waterbottle26. “It's a bit more official for some having it on paper, that way if your mind gets foggy or you forget to tell a nurse something, it will always be right there in black and white.”
Birthing room: A labor-and-delivery room equipped for childbirth, often designed to feel comfortable and homey.
Bishop score: A score your provider uses to estimate how ready your body is for labor. It's based on cervical effacement and dilation (how much your cervix has softened and opened), the baby's station (how far down the head has moved), and the position of the cervix.
Bladder: The organ that holds urine.
Blastocyst: The rapidly dividing fertilized egg once it enters the mother's uterus.
Blighted ovum: A fertilized egg that fails to form into a baby. A blighted ovum is a type of miscarriage.
Blood pressure: The amount of pressure blood exerts against the walls of the arteries. During pregnancy, blood pressure drops toward the second trimester and then rises again in the third trimester. High blood pressure during pregnancy may be a sign of preeclampsia.
Bloody show: A small amount of blood-tinged mucus that appears as the cervix softens, thins, and starts to open. Bloody show can mean labor is on the way — though “on the way” may mean hours or days. See mucus plug.
Body mass index (BMI): A measure that compares weight to height. To calculate BMI: multiply weight (in pounds) by 703 and divide that number by height (in inches) squared.
Bradley Method: This series of childbirth education classes emphasizes deep, slow breathing and relaxation. It also focuses on partner-supported labor — your coach helps guide and comfort you throughout.
Bradycardia: A slower-than-normal heart rate. For a baby, that means fewer than 100 beats per minute.
Braxton Hicks contractions: Irregular or "practice" contractions starting around the eighth month that prepare the uterus for labor. Unlike true labor, Braxton Hicks contractions aren't usually painful and don't get stronger and closer over time. Also called false labor or prodromal labor.
Breaking of water: The bursting of the sac holding the amniotic fluid. Your water can break on its own, or your practitioner may break the water to speed up a labor that has slowed (see amniotomy).
Breastfeeding: Feeding a baby with breast milk from the breast. Breastfeeding offers health benefits for both you and your baby — and it can be a sweet bonding experience.
Breech position/presentation: When the baby's bottom or feet, instead of the head, face the mother's cervix as labor nears. Three to 4% of full-term babies are in breech position.
Brow presentation: When a baby's head is slightly extended during labor so that the brow, not the top of the head, enters the birth canal first.
C
Candida: A yeast that can overgrow and cause an infection.
Carpal tunnel syndrome: Numbness, tingling, or pain in the hand and arm caused by pressure on a nerve in the wrist. Carpal tunnel syndrome caused by pregnancy swelling usually goes away after delivery.
Catheter: A small, flexible tube used to drain fluids from the body. During labor, a catheter may be placed if you have an epidural and can't empty your bladder on your own.
Cephalic presentation: When the baby is positioned head-down in the pelvis as birth approaches. This is the most common and ideal position for delivery.
Cephalopelvic disproportion (CPD): When a baby's head is too large to pass safely through the mother's pelvis. Cephalopelvic disproportion usually leads to a cesarean birth.
Cervical cerclage: A stitch placed in a weak or incompetent cervix to help keep it closed and support a pregnancy to term.
Cerebral palsy (CP): A condition caused by a prenatal brain defect or brain injury during pregnancy or birth. Cerebral palsy affects movement, muscle tone, and posture. Some children may also have seizures or learning disabilities.
Certified nurse-midwife (CNM): A registered nurse with advanced training in midwifery. CNMs are licensed by the state and usually work in collaboration with physicians.
Certified professional midwife (CPM): A midwife certified by the North American Registry of Midwives (NARM). CPMs generally assist only in home births.
Cervical cap: A small, dome-shaped birth control device that fits over the cervix to block sperm from entering.
Cervical mucus: The fluid produced by the cervix during the menstrual cycle. Around ovulation the cervical mucusbecomes stretchy and clear, like raw egg whites — a sign that conception is more likely. At other times it's thicker, white, and cloudy.
Cervical os: The opening of the cervix. During most of pregnancy, the cervical os stays closed. During labor (or shortly before) it softens, thins, and dilates up to 10 centimeters.
Cervical ripening: The process of softening and thinning the cervix in preparation for labor. It can happen naturally or be encouraged with medications like prostaglandins.
Cervidil: A medication used to ripen or soften the cervix before labor is induced. Cervidil is[KM1] the brand name of the drug dinoprostone.
Cervix: The narrow, lower end of the uterus. During labor, the cervix softens, thins and opens to allow the baby to leave the uterus.
Cesarean section (C-section): A surgical birth in which a baby is delivered through incisions in the abdomen and uterus. A cesarean section is used when a woman can't safely give birth vaginally.
Chadwick's sign: An early sign of pregnancy. The cervix and/or vagina turn a deep bluish-purple color due to increased blood flow.
Chlamydia: A common sexually transmitted disease, often with no visible symptoms. Untreated, chlamydia can cause infertility. It can also be passed to a baby during birth, leading to eye infection or pneumonia. It’s treatable with antibiotics, and newborns receive preventative antibiotic eye ointment at birth.
Chloasma: Also called the melasma or the mask of pregnancy. Hormones can cause darker patches on the forehead, cheeks, or nose. It's more common in women with darker skin and usually fades after delivery.
Chorioamnionitis: A bacterial infection of the membranes and the amniotic fluid surrounding the fetus. Chorioamnionitis can cause an infection in your baby, and it's been linked to preterm labor. So it’s important that it be treated as soon as possible.
Choriocarcinoma: A cancer that develops in the uterus, in most cases during or after pregnancy. Choriocarcinoma is extremely rare and responds well to treatment.
Chorionic villus sampling (CVS): A diagnostic test performed between 10 and 13 weeks of pregnancy. A small sample of tissue from the cells that line the placenta (called the chorionic villi) are removed through the cervix or abdomen with a needle and tested for chromosomal or genetic abnormalities. Chorionic villus sampling is available to all pregnant women, but it's especially recommended for women at increased risk.
Chromosomal abnormality: A problem with the chromosomes (either inherited or caused by a mutation) that can lead to Down syndrome or other abnormalities. About half of all first-trimester miscarriages are thought to result from chromosomal abnormalities.
Chromosome: The part of the cell that carries genetic information.
Chronic hypertension: Ongoing high blood pressure that's present before pregnancy.
Cleansing breath: Part of the Lamaze technique of childbirth, the cleansing breath is a deep inhalation through the nose and exhalation through the mouth. It's used at the beginning and end of a contraction to help restore normal breathing and reduce stress.
Cleft lip: A birth defect in which the upper lip doesn't fully form, leaving an opening or groove. A cleft lip can be repaired with surgery, usually performed before the baby is a year old.
Cleft palate: A birth defect where the roof of the mouth doesn't close properly. Surgery to repair a cleft palate is usually performed as early as possible, usually between 9 months and 14 months.
Clubfoot: A birth defect in which the foot or ankle turns inward. Club foot is treated with exercises, splinting, or surgery.
Coccyx pain: Pain in the tailbone area (coccyx) after giving birth, often due to pressure or injury during delivery.
Colostrum: The yellowish fluid secreted by the breasts before the production of true breast milk. Colostrum is rich in fats, protein, and antibodies. Some women notice small amounts of colostrum during pregnancy.
Complementary and alternative medicine (CAM): A group of healing approaches that focus on the body's natural ability to heal itself with the use of herbs, physical manipulation, and the mind. Some examples of CAM that can be used during pregnancy include: acupuncture, acupressure, biofeedback, chiropractic medicine, massage, hydrotherapy, and hypnosis.
Complete miscarriage: A miscarriage in which all pregnancy tissue is expelled from the uterus. Learn what happens after a miscarriage and how to cope.
Conceive: To begin a pregnancy, when a sperm fertilizes an egg.
Conception: When a sperm and egg join to form a single cell, usually in the fallopian tube. The fertilized egg travels io the uterus, where it implants in the lining.
Congenital disorder: A condition existing at or from birth.
Constipation: Bowel movements that are irregular, hard, dry, and difficult to push out. Constipation is a common pregnancy complaint.
Contraception: Methods to prevent a woman from becoming pregnant. Learn about birth control options after pregnancy.
Contraction: The strong, rhythmic tightening of the uterus during labor. True contractions grow stronger, longer, and closer together to help open the cervix and move the baby through the birth canal.
Contraction stress test (CST): A test that checks how the baby reacts to contractions. Oxytocin is given to the mother, to stimulate contractions, while baby's heart rate is monitored.
Convulsion: A series of involuntary muscle spasms.
Cord: The flexible cord of tissue connecting your baby to the placenta. The umbilical cord brings oxygen and nutrients you to your baby and removes waste products..
Cord blood banking: Collecting and storing blood from the baby's umbilical cord after birth. Some parents privately bank cord blood in case it's needed later for treatment of a serious disease in the child or another family member. Others donate cord blood to public banks.
Cord blood harvesting: The process of collecting cord blood from the umbilical cord and placenta after they're clamped and cut.
Cord compression: When the umbilical cord is squeezed during labor and/or delivery, which can reduce blood flow and oxygen to the baby.
Cord knots: When the umbilical cord becomes knotted, either during delivery or when the baby moves around in utero. Cord knots usually remain loose and pose no threat, but a tight knot can restrict blood flow.
Cord prolapse: When the umbilical cord slips through the cervix ahead of the baby during delivery. If the prolapsed cord is compressed, it may cut off the baby's blood and oxygen supply.
Corpus luteum: A cluster of cells in the ovary that forms after ovulation. It produces progesterone and estrogen and helps sustain early pregnancy until the placenta takes over at about 10 weeks.
Corpus luteum cyst: A cyst that forms if the corpus luteum doesn't shrink as expected. It rarely presents a problem, but your practitioner will monitor its size as a precaution.
Cortisol: A stress hormone that rises naturally during pregnancy.
Couvade syndrome: When a father-to-be experiences pregnancy symptoms in response to his partner's pregnancy, such as weight gain, backache, food cravings, and mood swings.
Cradle hold: A well-known breastfeeding position. The baby rests on his side, with his head in the bend of your elbow on the side where he's nursing.
Crossover hold: The breastfeeding position where you support your baby's head with the hand opposite the breast he's nursing from.
Crowning: The moment in labor when your baby's head has reached the external vaginal opening and can be seen from the outside. (If you use a mirror, you can see the top of your baby's head!)
Crown-to-rump length: The measurement of a fetus's size from the top of the head to the buttocks. This measurement is usually used during a first-trimester ultrasound to determine the gestational age of the baby.
Cystic fibrosis (CF): An inherited condition that affects the lungs and digestive system. There's no cure for cystic fibrosis, but treatments continue to improve.
Cytomegalovirus (CMV): A common and highly contagious viral infection. If contracted during pregnancy, cytomegalovirusmay lead to hearing loss, vision problems, and behavioral problems in the baby.
Want more week-by-week guidance and tips during your pregnancy? Check the What to Expect app, where you'll find help every step of the way.
D
D&C: Abbreviation. See dilation and curettage.
Deep vein thrombosis (DVT): A blood clot that develops in a vein deep in a limb. Deep vein thrombosis is uncommon but happens more often during pregnancy.
Dehydration: When the body loses more fluid than it takes in. You'll need to drink extra water to stay hydrated during pregnancy.
Demerol: A pain-relief medication sometimes used during labor and delivery.
Depo-Provera: A form of birth control. Depo-Provera is a high dose of the hormone progestin, which is injected every three months.
DES: A synthetic estrogen once given to women to prevent miscarriage. Daughters of women who took DES while pregnant may have a higher risk of certain cancers and fertility problems. According to the National Cancer Institute, DES was given to women between 1940 and 1971.
Diabetes: A condition in which the body doesn’t produce enough insulin, resulting in too much sugar in the bloodstream.
Diaphragm: A barrier birth control method that covers the cervix and prevents sperm from reaching the egg.
Diastasis: A separation of abdominal muscles that run down the center of the stomach, from the bottom of the rib cage to the top of the pubic bone. Diastasis recti can happen during pregnancy (though it's often not detectable until after birth), and the muscles usually return to normal after delivery.
Diastolic blood pressure: The lower number in a blood pressure reading. It reflects the amount of pressure in your arteries when your heart is relaxed between beats.
Dilation: The opening of the cervix during labor. Dilation is measured as the diameter of the cervix in centimeters.
Dilation and curettage (D&C): A procedure in which the cervix is dilated, and the contents of the uterus are removed by suction or scraping. D&C is often done after an incomplete miscarriage.
Docosahexaenoic acid (DHA): A polyunsaturated omega-3 fatty acid that's a major building block of the brain and eyes. Getting enough DHA during pregnancy and breastfeeding is important for your baby's brain and eye development.
Doppler: A handheld ultrasound device that's used to amplify the sound of a baby's heartbeat during pregnancy.
Doula: Also called childbirth assistants, doulas are specially trained to provide comfort and support during labor and delivery. A doula often acts as a liaison among the practitioner, nurses, and parents-to-be. Some doulas will also provide at-home assistance after the baby is born.
Down syndrome: The most common chromosomal abnormality, Down syndrome results when a baby has an extra copy of chromosome number 21. It's associated with developmental delays, as well as some medical concerns, such as heart defects.
Dropping: Also known as lightening, dropping is when your baby settles lower into your pelvis in preparation for birth. In first pregnancies it often happens a few weeks before labor; and in later pregnancies it may not happen until labor begins.
Due date: The estimated date your baby might be born. The due date is typically based on the first day of your last menstrual cycle. See Naegele's rule.
Dystocia: When labor doesn’t progress as expected. Labor dystocia is when contractions don't intensify and cervical change stops. Shoulder dystocia happens when a baby's shoulders get stuck after the head is delivered.
E
Early term: A baby born between week 37 and week 39 of pregnancy.
Eclampsia: A condition that can occur when untreated preeclampsia progresses to involve the central nervous system, leading to seizures. Eclampsia is a serious but rare condition that can develop late in pregnancy, during labor, or in the early postpartum stage. Delivering the baby is the only cure.
Ectopic pregnancy: When a fertilized egg doesn’t enter the uterus, but instead implants elsewhere, usually in the fallopian tube. Symptoms of an ectopic pregnancy can include abnormal bleeding, severe abdominal pain, or shoulder pain. The ectopic pregnancy must be surgically removed to prevent rupture and damage of the fallopian tubes. Also called extrauterine pregnancy.
Edema: Swelling caused by fluid buildup in the tissues. About 75% of pregnant women experience edema in their ankles and feet.
Effacement: Also referred to as ripening, effacement is the thinning and softening of the cervix in preparation for delivery. The cervix starts out more than an inch thick and ends up paper-thin.
Egg: A woman's reproductive cell, produced in the ovaries. When fertilized by sperm, it can develop into an embryo. Also called an ovum.
Egg donation: When a woman provides her eggs to help another woman conceive. The donor's ovaries are stimulated by drugs to produce multiple eggs, which are then retrieved, fertilized, and transferred to the recipient's uterus.
Ejaculate: Semen, the fluid that contains sperm and is released from the penis.
Ejaculation: The release of semen from the penis during orgasm.
Electronic fetal monitor: A device that tracks a baby's heartbeat and the mother's contractions during pregnancy or labor. Electronic fetal monitoring can be done externally or internally.
Embolism: A blood clot that breaks free and blocks blood flow in a vessel.
Embryo: A developing baby from implantation through 8 weeks after conception. After that, it's called a fetus.
Embryonic stage: Weeks 2 through 8 after conception.
Embryo transfer: An assisted reproductive technology in which a fertilized egg (embryo) is placed into the uterus.
Endodermal germ layer: The innermost layer of cells in the early embryo. Also known as the endoderm or entoderm, it eventually forms organs like the digestive system, lungs, bladder, urethra, and vagina.
Endometriosis: A condition where endometrial cells (the tissue that lines the uterus) grow outside the uterus, most often on the ovaries, fallopian tubes, or in the abdominal cavity. Endometriosis growths aren't dangerous, but they can be painful and make it more difficult to get pregnant.
Endometrium: The lining of the uterus, where the embryo implants.
Endorphin: A natural hormone that reduces pain and promotes a feeling of calmness. Endorphin levels rise during labor.
Enema: A procedure that empties the bowels. It’s no longer routinely used during labor.
Engaged: When the baby's head settles down into the pelvis in preparation for birth.
Engagement: See dropping.
Engorgement: Swollen and tender breasts postpartum. Engorgement often happens when mom's milk comes in (usually two to seven days after delivery). Symptoms usually disappear in a few days, when nursing is well established.
Epidural: A common form of pain relief during labor. Medication is placed into the epidural space near the base of the spine. An epidural numbs the lower body and reduces pain significantly by making the mother unable to feel contractions during labor and delivery.
Episiotomy: A cut made in the perineum to enlarge the vaginal opening just before the emergence of the baby's head. Episiotomies are no longer routine.
Estimated date of birth (EDB): A term used by midwives instead of "due date." It's based on the first day of a woman's last menstrual cycle. See Naegele's rule.
Estimated date of confinement (EDC): An archaic term for the estimated date a baby might be born (and mom and baby confined to home). It’s based on the first day of a woman's last menstrual cycle. See Naegele's rule.
Estimated date of delivery (EDD): The estimated date a baby might be born. It's based on the first day of a woman's last menstrual cycle. See Naegele's rule.
Estriol: A hormone produced by the fetus and passed into the mother's bloodstream. Levels of this hormone can be tested via a blood test (quad screen) during the second trimester. Low levels (combined with high levels of other hormones) can indicate an increased risk of Down syndrome.
Estrogen: A hormone produced in the ovaries that works with progesterone to regulate menstruation.
Exclusive breastfeeding: Feeding your baby only breast milk — no formula, water, or other supplements.
Expressing breast milk: Removing milk from the breasts to store for a later feeding. Breast milk can be expressed by hand, but most moms use a pump to express breast milk.
External cephalic version (ECV): A procedure used to turn a breech baby to the head-down position using gentle pressure on the abdomen and ultrasound guidance. Also called version.
“I had an ECV and it was successful,” says What to Expect Community member Eatallthesalad. “Wasn't painful, just uncomfortable.” Community mom surprised 09 says, “My belly was sore after! Unfortunately it didn't work but I'm glad I tried.”
External fetal monitoring: Tracking your baby's heartbeat and your contractions using sensors placed on your belly.
Extrauterine pregnancy: See ectopic pregnancy.
F
Failure to progress: When labor slows down or stops, often because contractions aren't strong enough or because the baby has trouble fitting through the pelvis. Your provider will monitor you and your baby closely and may recommend ways to help labor move along.
Fallopian tubes: The small tubes that carry an egg from the ovary to the uterus. Most fertilization — when egg meets sperm — happens here.
False labor: See Braxton Hicks.
Family and Medical Leave Act (FMLA): A U.S. law that gives eligible employees up to 12 weeks of unpaid, job-protected leave to care for a new baby (birth or adoption) or a seriously ill close family member. Companies must have at least 50 employees to be covered.
Family practitioner: The updated term for the general practitioner who provides medical service for the whole family.
Fecal incontinence: Difficulty controlling bowel movements. Sometimes, a severe tear or large episiotomy during labor can cause fecal incontinence.
Fertility: Being able to conceive and carry a baby to term. (Curious how to boost your chances? See how to get pregnant faster. )
Fertility medications: Drugs that help stimulate ovulation or correct hormonal issues that may be preventing pregnancy. Common fertility drugs include Clomid (clomiphene citrate), Femara (letrozole), hormone shots (gonadotropins), Parlodel (bromocriptine), and Dostinex (cabergoline).
Fertility specialist: An OB/GYN with extra training in diagnosing and treating fertility challenges.
Fertilization: When an egg and sperm join together to form an embryo. Fertilization usually happens in one of the fallopian tubes.
Fertilization age: The age of the developing baby based on the actual conception date. (Most pregnancy dating uses the last menstrual period instead.)
Fetal acoustic stimulation: A quick test that uses gentle sound or vibration on mom's belly to see how the baby responds. It can help check on baby's well-being. Also called vibroacoustic stimulation (VAS).
Fetal alcohol effects (FAE): Developmental or behavioral issues that can result when a pregnant person drinks moderate amounts of alcohol (one or two drinks daily). These signs often become clearer in childhood.
Fetal alcohol syndrome (FAS): A serious condition caused by heavy drinking (four or more drinks a day) during pregnancy. Fetal alcohol syndrome can lead to physical and developmental disabilities in the baby.
Fetal anomaly: An abnormality in the developing baby.
Fetal blood sampling: A genetic test that screens blood from a baby’s umbilical cord for abnormalities.
Fetal diagnostic testing: Tests to check on the well-being of the baby during pregnancy.
Fetal distress: When a baby isn't getting enough oxygen. Signs of fetal distress may include a slowed heartbeat or decreased movement. Immediate medical action — sometimes delivery — may be needed.
Fetal fibronectin (FFN): A protein found near the cervix. If it's detected in the third trimester, it may mean labor could start soon. This test is mainly used when there's concern about preterm labor.
Fetal growth restriction (FGR): Slower than normal growth of a baby in the womb. Babies measuring below the 10th percentile for gestational age may be diagnosed with fetal growth restriction.
Fetal heart rate: The rate of the baby's heartbeat while in the uterus or during delivery. Normal fetal heart rate is between 120 and 160 beats per minute.
Fetal loss: When a pregnancy ends because the fetus dies in the uterus.
Fetal-maternal exchange: The transfer of oxygen and nutrients from mom to the baby through the umbilical cord and the transfer of waste from the baby to the placenta.
Fetal monitoring: Keeping an eye (or ear) on the baby’s heartbeat and your contractions during labor. This may be done periodically or continuously. (See electronic fetal monitoring.)
Fetal movement counts: After 27 weeks of pregnancy, women are encouraged to count how often their baby moves within an hour. Times can vary, but 10 or more fetal movements within one to two hours is reassuring. Also called “kick counts.”
Fetal period: The stage of development following the embryonic stage, lasting from eight weeks gestation until birth.
Fetal presentation: The position of the baby inside the uterus — feet-down (breech) or head-down (vertex).
Fetal scalp stimulation: A test to check on how the baby is doing while inside the uterus. The provider gently rubs or presses on the baby's scalp to see how the heart rate responds.
Fetoscopy: A diagnostic procedure in which a doctor inserts a laparoscope (a tiny camera) through a small incision in the abdomen to look for any abnormalities in the baby.
Fetus: The name given to a developing baby from eight weeks until birth.
Fever: When body temperature rises above its normal level. A temperature above 100.4 degrees F is considered a fever. A fever is the sign of an immune system at work and usually indicates an infection.
Fibroids: Growths on the uterus. Fibroids can be small or large and are almost always benign (non-cancerous).
Focal point: A spot in a room — on the ceiling, floor, wall, or a photograph or picture, for example — that you can focus on during contractions to help you stay centered and calm.
Folic acid: A B vitamin crucial before and during pregnancy. Folic acid helps prevent certain birth defects, including neural tube defects like spina bifida. The natural form (in foods like leafy greens) is called folate. Prenatal vitamins contain folic acid.
Follicle: A tiny sac in the ovary that holds an egg and releases it during ovulation.
Follicle-stimulating hormone (FSH): A hormone produced by the pituitary gland that helps eggs mature in the ovaries.
Fontanelles: The soft spots on a baby's head that allow the skull to compress during birth and pass through the birth canal. At birth, there are six fontanelles. They typically close by a child's second birthday.
Football hold: The breastfeeding position where the baby is tucked under your arm — like a football — while facing you.
Footling breech: A breech position where one or both of the baby's legs are positioned downward near the cervix.
Forceps: Tong-shaped instruments that are inserted into the vagina and placed around the baby's head. Forceps might be used if your baby is struggling to make his way through the birth canal during childbirth.
Frank breech: When the baby is positioned buttocks down and his legs are stretched up with his feet near his head.
Fraternal twins: Twins who develop from two separate eggs fertilized by two separate sperm. They can look alike — or not at all.
Full-term: A baby born between 39 and 41 weeks of pregnancy.
Fundal height: The distance between the top of your uterus (fundus) to your pubic bone. The fundal height is measured to keep track of your baby's growth as your pregnancy progresses.
Fundus: The rounded top part of the uterus — the place your provider measures during prenatal visits.
G
Gamete intra-fallopian transfer: A fertility treatment similar to IVF. Eggs and sperm are placed directly into the fallopian tube so fertilization can happen naturally inside the body.
General anesthesia: Medication that puts you completely to sleep and blocks all pain. It's rarely used in labor but may be needed for certain emergency C-sections.
General practitioner: See family practitioner.
Genetic: Something determined by your genes. Many inherited traits and some medical conditions are genetic.
Genetic counseling: A meeting with a healthcare professional who helps parents understand their chances of having a baby with a genetic condition. The counselor will explain available screening, testing, and options.
Genetic disorder: A disease or condition caused by abnormal genes.
Genetic screening: Any test used to determine the risk of genetic abnormalities. Genetic screening can be done before you become pregnant or during pregnancy.
Genital herpes: A virus that affects the genital area. A mother with untreated genital herpes can pass the infection onto her newborn during childbirth.
Genitals: The external sex organs.
German measles: Also called rubella, German measles is a highly contagious viral illness causing a mild red rash. Women who haven't had German measles should make sure they're immunized before conception, because rubella can cause serious birth defects in a baby if a pregnant woman is infected.
Gestation: Another word for pregnancy, the time a baby is carried in the uterus, counted from the first day of the last menstrual period.
- Early-term gestation: 37 to 39 weeks
- Full-term gestation: 39 to 41 weeks
- Late-term gestation: 41 to 42 weeks
- Post-term gestation: 42 weeks or longer
Gestational age: The age of the baby while in the uterus, counted from the first day of the last menstrual period. This is how pregnancy is typically dated.
Gestational diabetes: A type of diabetes that develops during pregnancy when blood sugar levels become too high because mom doesn't produce enough insulin. Gestational diabetes can be treated, and it usually disappears after pregnancy.
Gingivitis: Red, tender, bleeding gums. Pregnancy hormones can make gums extra sensitive. If left untreated, gingivitis can develop into periodontitis, a serious form of gum disease.
Glucose: A type of sugar present in the blood and your body's main source of energy.
Glucose challenge test: A routine test done in pregnancy to check for gestational diabetes. You'll drink a sweet glucose drink and have your blood drawn an hour later. If your glucose challenge test results are high, your provider will order a glucose tolerance test. Also called a glucose screening test.
Glucose screening test: See glucose challenge test.
Glucose tolerance test: This is the next step if a glucose screening test comes back elevated. You’ll fast before this three-hour study, during which you'll drink a concentrated sweet glucose drink and have blood drawn at specific intervals. If the blood work comes back again with elevated numbers, there's a high probability of gestational diabetes.
Glucosuria: Glucose (sugar) found in the urine. It can be a sign of elevated blood sugar.
Gonorrhea: A sexually transmitted disease. If untreated during pregnancy, it can lead to preterm delivery and cause serious health issues for the newborn, including eye infections.
Gravida: The medical term for a pregnant woman or the number of times a woman has been pregnant.
Group B streptococcus (GBS): A type of bacteria that can be found in the vagina or rectum. Most women have no symptoms, but Group B Strep can be dangerous for newborns if passed on during birth. Routine testing is done between weeks 35 and 37. If the result is positive, mom will receive either IV antibiotics during labor or oral antibiotics during the last weeks of pregnancy.
GYN: Abbreviation. See gynecologist.
Gynecologist (GYN): A physician who specializes in women's reproductive health. See OB/GYN.
H
Habitual miscarriage: Three or more pregnancy losses in a row. If this happens, your provider may recommend testing to look for underlying causes. Many women go on to have healthy pregnancies afterward. Also called recurrent miscarriage.
HCG: Abbreviation. See human chorionic gonadotropin.
Heartburn: A burning feeling in the chest or throat caused when stomach acid moves upward into the esophagus. During pregnancy, hormones relax the valve at the top of the stomach that usually prevents digestive acids from going back up. And your growing uterus adds extra pressure — both of which can make heartburn more common.
Hegar's sign: The softening of the area between the cervix and the uterus in early pregnancy. Used by physicians and midwives as a sign of pregnancy.
HELLP syndrome: An abbreviation for hemolysis, elevated liver enzymes, and low platelets. HELLP is a rare, serious condition that happens on its own during pregnancy or along with preeclampsia. Symptoms may include severe upper-right abdominal pain, nausea, vomiting, and sometimes intense itching. The treatment is to deliver the baby.
Hematocrit: In a blood test, the number (or percentage) of red blood cells.
Hemoglobin: A type of protein in red blood cells that carries oxygen to throughout the body, including to your growing baby.
Hemophilia: A hereditary blood disorder in which blood doesn't clot properly. It almost always occurs in males, though females can be carriers.
Hemorrhage: Heavy bleeding. Postpartum hemorrhage is relatively rare but serious.
Hemorrhoids: Swollen, bulging veins in the rectum — similar to varicose veins — that can itch, hurt, or bleed. Hemorrhoids are very common in pregnancy because of increased blood flow, pressure from the uterus, and constipation. They can also appear after pushing during labor. Constipation can cause hemorrhoids or make them worse.
Hepatitis B: An infection of the liver caused by a blood-borne virus or through sexual contact. Hepatitis B can be passed from mother to child during pregnancy, though newborns can be treated at birth.
Herpes: A sexually transmitted disease affecting the genital area. A woman with active, untreated genital herpes can pass the virus onto her newborn during childbirth.
High-risk pregnancy: A pregnancy with a higher-than-normal risk of developing complications. High risk may be related to age, carrying multiples, certain medical conditions (like gestational diabetes or hypertension), or issues like placenta previa.
HIV: The human immunodeficiency virus that causes AIDS, often sexually transmitted. If untreated, an HIV-positive mothercan transmit the virus to her baby during pregnancy, birth, or breastfeeding. With proper medical care, transmission can often be prevented.
Home birth: Labor and delivery that takes place at home. Home births usually have a midwife present.
Home pregnancy test: A test that you take at home that detects hCG — the pregnancy hormone — in your urine. Some home pregnancy tests can be used even before the day a menstrual period is due.
Hormone: A chemical secretion that the body produces to regulate everything from growth and mood to metabolism, fertility, and pregnancy.
Human chorionic gonadotropin (hCG): A hormone produced during pregnancy. Excreted in urine, hCG is used to detect pregnancy.
Hydatidiform mole: An abnormal pregnancy, called a molar pregnancy, in which tissue grows inside the uterus but no fetus develops. It’s rare and usually found early through symptoms or ultrasound.
Hydramnios: When there is too much amniotic fluid in the uterus. Also called polyhydramnios.
Hydrocephalus: A relatively rare condition caused by an abnormal amount of fluid in the baby's brain. Hydrocephalus is sometimes the first sign of spina bifida.
Hydrotherapy: The therapeutic use of warm water, usually in a spa bathtub. A complementary and alternative medicine (CAM) technique, hydrotherapy is often used to help a laboring woman relax and reduce her discomfort.
Hyperemesis gravidarum: A severe form of morning sickness that involves intense, persistent nausea and vomiting during pregnancy. Hyperemesis gravidarum can sometimes lead to dehydration and hospitalization.
Hyperglycemia: Having too much glucose in the blood. Hyperglycemia is usually a sign of gestational diabetes.
Hypertension: High blood pressure. If you have chronic hypertension, you'll be monitored carefully during pregnancy.
Hyperthyroidism: Elevated levels of the thyroid hormones. If untreated, hyperthyroidism can cause pregnancy complications.
Hyperventilation: Breathing too fast, leading to dizziness and tingling. It sometimes happens during labor when breathing patterns become irregular.
HypnoBirthing: A childbirth method that uses guided relaxation and hypnosis techniques. HypnoBirthing is used to help reduce fear, tension, and pain during labor.
Hypnosis: A complementary therapy that uses deep relaxation and focused attention. Some people use hypnosis to manage labor pain, turn a breech baby, or help prevent preterm labor.
Hypotension: Low blood pressure. Some women experience a drop in blood pressure when they get an epidural during labor.
Hypothyroidism: When the thyroid doesn't make enough thyroid hormone. If untreated, it can cause pregnancy or postpartum concerns, but it’s easily managed with medication.
Hypoxia: When a baby isn't getting enough oxygen, often due to issues like cord compression or low blood pressure in the mother. Providers act quickly to correct it.
Hysterectomy: The surgical removal of the uterus. After a hysterectomy, pregnancy is no longer possible.
I
Identical twins: Identical twins are formed when one fertilized egg divides, creating two babies with the exact same genetic makeup. Identical twins usually look remarkably alike and are always the same sex. Learn about the different types of twins.
Immune system: Your body's built-in defense team that protects you from germs, infections, and illness.
Immunization : A vaccine, usually given as a shot, that trains your immune system to fight off certain infections. Some vaccines are important to get before and during pregnancy, and others should wait until after your baby is born.
Implantation: When a fertilized egg attaches itself to the lining of the uterus. Implantation is the very beginning of pregnancy.
Inborn errors of metabolism: Rare genetic defects in which a baby is missing an enzyme or other chemical substance needed to break down food. Many of these can be detected before birth or shortly after delivery.
Incision: A cut made to open the body during surgery. During a C-section, an incision is made in the abdomen and uterus to deliver your baby.
Incompetent cervix (cervical insufficiency): When the cervix begins to open too early — before labor starts — due to pressure from the growing uterus. An incompetent cervix can cause a miscarriage in the second trimester or preterm labor in the third. A common treatment is a stitch called a cerclage to help keep the cervix closed.
Incomplete miscarriage: A miscarriage in which some pregnancy tissue remains in the uterus. A D&C is often used to remove the remaining tissue.
Incontinence: Difficulty controlling bladder or bowel movements. Incontinence is common during pregnancy thanks to hormones and extra pressure on the bladder.
Induction: When labor is started artificially — using medications like Pitocin or prostaglandins, or by breaking the water. Induction may be recommended if you're past your due date or contractions haven't started even though your water has broken.
Inevitable miscarriage (or spontaneous abortion): A pregnancy with bleeding, cramping, and an open cervix where a miscarriage cannot be prevented.
Inferior vena cava: The vein responsible for returning blood from the lower body to the heart. Lying on your back during pregnancy can compress the inferior vena cava and make you feel dizzy or lightheaded.
Infertility: The inability to conceive or carry a child to term.
Inhibin-A: A hormone made by the placenta. It’s one of the markers checked during the second-trimester quad screen. Higher-than-expected levels — along with other elevated markers — may indicate an increased risk for Down syndrome.
Insomnia: Trouble falling or staying asleep. Insomnia is especially common in the third trimester. Use the MyJournal tool in the What to Expect app to track your wakeful hours and possible triggers.
Insulin: A hormone that helps move sugar (glucose) from your bloodstream into your cells for energy.
Intracytoplasmic sperm injection (ICSI): An assisted fertilization technique in which a single sperm is injected into a single egg and the resulting embryo is transplanted into the uterus.
Intrapartum fever: A fever that develops during labor or delivery.
Intrauterine device (IUD): A plastic or metal device placed in the uterus to prevent pregnancy. IUDs are often a good choice for moms looking for long-term birth control.
Intrauterine insemination (IUI): See artificial insemination.
Intravenous catheter (IV): A small, hollow, flexible tube placed in a vein so that fluids or medications can be given. You may have an IV during labor.
In utero: Inside the uterus.
Inverted nipples: When the nipples retract into the breast tissues instead of sticking out when cold or when the breast is compressed at the edge of the areola. Inverted nipples can make it harder for a breastfeeding baby to latch without some extra help.
In vitro fertilization (IVF): A fertility treatment in which eggs and sperm are combined outside the body. After fertilization, one or more embryos are transferred to the uterus. There are many steps to in vitro fertilization, and one cycle usually takes four to six weeks.
Involution: The postpartum process of the uterus returning to its pre-pregnancy size after the birth of a baby.
Iron deficiency anemia: A low level of red blood cells, usually due to a shortage of iron. Detected through a blood test, iron deficiency anemia causes symptoms like fatigue, weakness, breathlessness, or dizziness. Eating iron-rich foods and taking an iron supplement — especially in the second half of pregnancy — helps your body keep up with the increased demand.
K
Kegel exercises: Tightening and relaxing the pelvic floor muscles in order to strengthen them. Doing Kegels during pregnancy and after birth can help prevent problems like urinary leakage.
L
Labia: The two sets of skin folds that protect a woman's genitals.
Labor: The process of childbirth. Labor begins with regular contractions that dilate (open) the cervix and ends after the baby — and then the placenta — are delivered.
Labor-delivery-postpartum room (LDPR): A hospital or birth center room where you'll labor, deliver, recover, and stay postpartum — all without having to move to a different room.
Labor-delivery-recovery room (LDR): A room where you experience labor, birth, and the early recovery period before being moved to a postpartum room.
Laceration: A tear in the perineal area that happens during childbirth.
Lactation: The production of breast milk that usually begins two to five days after delivery.
Lactation consultant (LC) or specialist: A person trained to assist breastfeeding women. A lactation consultant can support you on your breastfeeding journey and help with problems such as latching, milk production, or sore nipples.
“I highly recommend it,” says What to Expect Community mom scabbers23 about seeing a lactation consultant. “I wish I would have done it sooner. . . it really helped.”
Lactose intolerance: Difficulty digesting lactose, the sugar found in dairy products. Symptoms of lactose intolerance include bloating, diarrhea, gas, or stomach cramps.
Lamaze: A childbirth preparation technique. Lamaze uses relaxation and rhythmic breathing patterns together with the support of a labor coach to help manage labor pain.
Lanugo: Soft, fine hair that covers a baby’s body by the middle of pregnancy. Lanugo begins to shed by the eighth month, but some babies are still born with a little fuzz.
Large for gestational age (LGA): A newborn weighing more than 90% of babies born at the same number of weeks of pregnancy.
Last menstrual period (LMP): The first day of your last menstrual period. This date is used to calculate the 40 weeks of pregnancy and your due date. See Naegele's rule.
Latching on: The way a baby takes the nipple and areola into the mouth to begin breastfeeding. A good latch is important for breastfeeding.
Latent labor: The first and longest phase of labor during which the cervix effaces (thins) and dilates (opens) to about three centimeters.
Late term pregnancy: A pregnancy between weeks 41 and 42. The pregnancy has gone past term (40 weeks) and is considered late but not yet postterm (or 42 weeks and beyond).
Laxative: A food or medicine that stimulates a bowel movement.
Lay midwife: An uncertified or unlicensed midwife who has no formal medical training but has experience with childbirth. Only a few states allow lay midwives to practice, and then only at home births.
Layette: A newborn’s first wardrobe and essentials — clothing, blankets, bibs, and other must-haves. See our layette checklistfor ideas.
LDPR: Abbreviation. See labor-delivery-postpartum-recovery room.
LDR: Abbreviation. See labor-delivery-recovery room.
Leboyer birth: A gentle birth method focused on reducing stress for newborns. It may include immediate skin-to-skin contact, dim lighting, baby massage, soft voices, or placing the baby in warm water.
Leg cramps: Painful leg spasms common at night during the second and third trimesters. Leg cramp pain can sometimes be relieved by straightening the leg and flexing the ankle and toes slowly up toward the nose.
Leopold's maneuvers: Hands-on techniques used by physicians and midwives to determine the baby's position The practitioner positions their hands on your abdomen and feels for the baby's head, back, and buttocks.
Let-down: An involuntary reflex that releases breast milk when your baby starts to suck. Sometimes let down can be slow, other times it can be overactive. Breastfeeding is easiest when it's just right.
“My letdown feels like a warm pins and needles sensation at the side of the breasts,” says What to Expect Community mom Blueskystarlight. “Tingling in nipples is how I would describe mine,” says member rls1322.
Leukorrhea: A thick, milky, mild-smelling vaginal discharge that's normal during pregnancy. It usually increases as pregnancy progresses and can get heavy at times.
Lightening: See dropping.
Linea alba: The light line running from the belly button to the pubic bone. During pregnancy, it darkens and is renamed the linea nigra.
Linea nigra: The dark vertical line that runs down the center of the abdomen to the top of the pubic bone. This darkening is caused by pregnancy hormones. The linea nigra may be more noticeable in dark-skinned women than those who are fair-skinned.
Listeriosis: A foodborne illness caused by bacteria found in certain foods — including unpasteurized milk products, undercooked meats, fish, shellfish, poultry, deli meats, and unwashed vegetables. The symptoms of listeriosis are similar to those of the flu. The illness can be transmitted in utero to a baby and lead to serious complications.
LMP: Abbreviation. See last menstrual period.
Local anesthesia: A medication that numbs a small area. You might receive a local before an epidural or an episiotomy.
Lochia: Postpartum vaginal discharge and bleeding that resembles a heavy period. Lochia continues after delivery up until about six weeks before tapering off.
Low birth weight baby: A full-term infant weighing less than 5 pounds 8 ounces at birth is considered low birth weight.
Luteinizing hormone: A hormone produced by the pituitary gland that helps regulate reproductive hormones and triggers the release of a mature egg during ovulation.
M
Macrosomia: A term for a baby who is very large at birth. Definitions for macrosomia vary, but 8 pounds 13 ounces or 9 pounds 15 ounces are common thresholds.
Magnesium sulfate: A medication used to prevent and treat eclampsia.
Magnetic resonance imaging (MRI): A type of imaging that uses magnets — not radiation — to give a clearer look at certain fetal conditions than an ultrasound can.
Malpresentation: When a baby is positioned in an unusual way during birth (for example, feet or shoulder first instead of the head).
Mammary glands: The milk-producing glands in the breast.
Mask of pregnancy: See chloasma.
Mastitis: A breast infection that often begins with a blocked milk duct. Symptoms include swelling, tenderness, redness, and fever. Treatment for mastitis includes massage, warm compress, continued breastfeeding, and usually antibiotics.
Maternal-Fetal Medicine specialist (MFM): An OB/GYN who specializes in caring for high-risk pregnancies. Also called a perinatologist.
Maternal serum alpha-fetoprotein screening (MSAFP). A blood test given between weeks 15 and 20 of pregnancy to screen for an increased risk of a birth defect. High levels of MSAFP may be associated with a neural tube defect, and low levels may be associated with Down syndrome. Abnormal results help determine whether more testing is needed.
Maternity center: See birth center.
Maternity leave: Paid or unpaid time off work to care for a new baby. See Family and Medical Leave Act. Some states and individual employers offer paid maternity leave and/or paternity leave.
Meconium: A newborn’s first stool. Meconium is thick, sticky, and greenish brown. It’s usually passed after birth, but sometimes babies pass it before delivery, which can tint the amniotic fluid.
Meconium aspiration: When a baby inhales meconium-stained fluid during or right before birth. Most babies with meconium aspiration recover quickly with a little help from the delivery team.
Meconium staining: When the baby passes meconium before birth and it mixes with the amniotic fluid.
Melasma: See chloasma.
Membranes: See amniotic sac.
Menstrual cycle: A woman’s monthly reproductive cycle. It includes thickening of the uterine lining, ovulation, and — if no pregnancy occurs — the shedding of that lining. Most cycles last 28 to 30 days.
Mercury: A toxic metal that can harm a developing baby's brain and nervous system. Mercury is found in high concentrations in certain types of fish — including shark, swordfish, tilefish, and king mackerel. Learn which fish are safe to eat during pregnancy.
Midwife: A trained professional who provides care to women during pregnancy and through labor and delivery. Midwives often take a holistic and woman-focused approach to pregnancy and childbirth, and many work alongside doctors.
Miscarriage: The loss of a pregnancy before 20 weeks. It's very common — occurring in about 15 to 20% of pregnancies. Most miscarriages happen in the first trimester, many before a woman even knows she's pregnant. Also called spontaneous miscarriage.
Misoprostol: A drug used to soften and open the cervix and induce labor.
Missed miscarriage (or spontaneous abortion): When an embryo or fetus has stopped developing but remains in the uterus. Some women wait for the pregnancy to pass naturally, while others choose a D&C.
Molar pregnancy: See hydatidiform mole.
Molding: The temporary reshaping of a baby's head to help its passage through the birth canal.
Montgomery's tubercles or follicles: The small, goosebump-like glands that appear on the areola during pregnancy.
Morning sickness: Nausea, vomiting, and smell aversions that affects more than 70% of pregnant women. Morning sickness, which can happen any time of day, usually begins at 4 to 8 weeks gestation and eases around weeks 14 to 16.
Moxibustion: A traditional Chinese treatment that combines acupuncture and burning herbs. In pregnancy it may be used to help turn a breech baby.
Mucus plug: See bloody show.
Multigravida: A woman who has previously been pregnant.
Multipara: A woman who has had one or more babies.
Multiple birth: When a woman delivers more than one baby at a time — twins,, triplets, or more.
Multiple pregnancy: A pregnancy with more than one fetus.
Mutation: A spontaneous change in a gene that occurs in an egg, sperm, or embryo. These changes are not inherited from a parent.
N
Naegele's rule: A method for estimating a pregnant woman's due date. Add 280 days to the first day of the last menstrual period. Developed in the 1800s by Franz Naegele, a German obstetrician.
Narcotics: Medications used to block or relieve the sensation of pain during labor and delivery, such as Demerol, a narcotic analgesic.
Natural childbirth: Labor and delivery without medication and/or medical intervention. You can have a natural birth at a birth center, at home, or in a hospital.
Nausea: A queasy feeling in the stomach that may or may not lead to vomiting. Nausea is very common in the first trimester.
Neonatal: The time from a baby's birth to four weeks of age.
Neonatal death: The death of a live-born baby anytime between birth and 4 weeks of age.
Neonatal intensive care unit (NICU): A special care nursery for sick or premature newborns. NICUs are staffed by trained specialists and equipped with advanced technology.
Neonate: A newborn.
Neonatologist: A physician who specializes in the care of newborns.
Nesting instinct: Toward the end of pregnancy, many pregnant women feel an urge to prepare for the impending birth. This burst of energy, called the nesting instinct, can lead an expectant mother to clean, cook, and tidy.
“I was cleaning out the crevices of our cabinets at 10 pm with hot water and detail brush,” says WhatToExpect Community mom sammiekaye16. “I also found myself intensely wanting to bake a ton of different baked goods. This is not something I would normally feel compelled to do — I’m typically quite lazy actually!”
Neural tube defect: A birth defect involving the baby's brain or spine.
Newborn: The term for a baby between birth and one month old. Also referred to as the neonatal period. Sometimes babies up to three months are considered newborn.
NICU: Abbreviation. See neonatal intensive care unit.
Nipple confusion: A newborn who switches back and forth between a bottle and a breast might experience confusion because the sucking techniques are different for each. Nipple confusion can make breastfeeding more difficult.
Nipple: The small projection near the center of the breast containing the outlets of the milk ducts.
Non-reassuring fetal status: Signs from monitoring tests suggesting that a baby may be in distress.
Nonstress test (NST): A test that monitors how a baby’s heart rate responds to fetal movements. If the heart rate doesn't respond as expected to fetal movement, the nonstress test results are considered non-reassuring. See oxytocin challenge test.
Nuchal cord: When the umbilical cord wraps around the baby's neck.
Nuchal fold thickness: A thickening of skin behind the baby's neck, visible via ultrasound, which may indicate an increased risk of Down syndrome or other conditions.
Nuchal translucency: An abnormal collection of fluid behind the baby's neck during the first trimester. Visible via ultrasound, nuchal translucency can indicate increased risk of a chromosomal disorder or other birth defects.
Nulliparous: A woman who has never delivered a baby.
Nurse-midwife: A registered nurse who has completed graduate training in midwifery. Most nurse-midwives have a collaborative relationship with a physician.
Nurse practitioner: A nurse who has completed a master's program in a specialty and is able to diagnose and treat conditions, as well as prescribe medications.
O
OB/GYN: Obstetrician-gynecologist. A physician specializing in women's reproductive health, pregnancy care, labor, and delivery. One of the types of pregnancy doctors.
Obstetrician: A physician specializing in obstetrics, the care of pregnant women and management of childbirth.
Obstetrics: The medical field focused on pregnancy, labor and delivery, and postpartum care.
Obstructed labor: When labor doesn't progress, often due to the baby's position, size, or the shape of the mother's pelvis.
Occiput anterior (OA) position: When the baby is head-down with the back of the head facing the mother's spine. This is the most common and optimal position for birth.
Occiput posterior (OP) presentation: When the baby is head-down but facing the mother's abdomen. This position can lead to prolonged labor and intense back pain, known as back labor.
Oligohydramnios: A condition in which there is too little amniotic fluid. Most pregnancies continue normally, but oligohydramnios can sometimes be a sign of fetal distress or complications.
Omega-3 fatty acids: Essential fatty acids, including DHA. DHA is essential for brain and eye development. Eating a diet rich in omega-3s during pregnancy and while nursing is extremely important.
Operative vaginal delivery: A vaginal birth assisted with tools such as forceps or a vacuum extractor.
Oral contraceptives: Birth control pills containing hormones that prevent ovulation.
Ovaries: The female reproductive organs that release eggs into the fallopian tubes, where they may be fertilized if sperm is present.
Ovulation: The monthly release of a mature egg from an ovary. A woman is most fertile around the time of ovulation.
Ovum: A human egg.
Oxytocin: A hormone secreted by the pituitary gland. When released, oxytocin causes uterine contractions. Pitocin is a synthetic form of the hormone, commonly used to induce or augment labor.
Oxytocin challenge test (OCT): See contraction stress test.
P
Palpation: A technique in which a doctor or midwife feels the mother's abdomen to determine the baby's position.
Pap smear: A routine test to check for abnormal cells on the cervix. A pap smear is usually performed at the first prenatal visit.
Paracervical block: An injection of a local anesthetic into the tissues around the cervix to relieve pain, sometimes during childbirth.
Partial molar pregnancy: An abnormal pregnancy in which there’s an abnormal mass and fetal tissues in the uterus. A partial molar pregnancy means two sets of chromosomes from the father mix with one set of chromosomes from the mother. (If no maternal chromosomes are present, it’s a complete molar pregnancy.)
Parturition: The act of giving birth.
Patient-controlled analgesia (PCA): When a laboring woman uses a pump to control the amount of IV pain medication she receives.
Peak day: The best time to conceive during the monthly cycle, usually the day of ovulation. Use our ovulation calculator and calendar to discover your most fertile days.
Pediatrician: A physician who specializes in treating infants, children, and adolescents.
Pelvic adhesions: Scar tissue from surgeries (such as a C-section or laparoscopy) or from pelvic inflammatory disease, which can interfere with reproductive organs.
Pelvic floor muscles: The muscles at the base of the pelvis that support the uterus, vagina, bladder, and rectum. These muscles can be strengthened with Kegel exercises.
Pelvic inflammatory disease (PID): A bacterial infection of the female reproductive organs, including the uterus, fallopian tubes, and cervix. PID can sometimes lead to infertility.
Pelvimetry: Measurements of the pelvis to determine whether a vaginal birth might be difficult.
Pelvis: The lower bony structure of the torso through which the baby passes during birth.
Percutaneous umbilical blood sampling (PUBS): A procedure that samples blood from the baby's umbilical cord while still in utero. This procedure can be used to run tests on the baby’s blood and to transfuse blood to the baby in utero.
Perinatal: The time before, during, and immediately following birth.
Perineal massage: A technique to gently stretch the perineum before childbirth to help reduce tearing or the need for an episiotomy.
Perineal tear: A rip in the skin or muscle between the vagina and the rectum.
Perineum: The area between the vagina and rectum. The perineum may stretch or tear during childbirth.
Periodontitis: A gum disease that increases a woman's risk of having a premature or low birth weight baby. Good oral health is especially important while you're pregnant.
Phenylketonuria (PKU): PKU is a genetic disorder in which the body lacks an enzyme needed for normal metabolism. If not carefully regulated by diet early in infancy, PKU can cause mental disability.
Pica: The urge some pregnant women have to eat nonfood items such as dirt, chalk, or clay. Often associated with iron-deficiency anemia.
Pitocin: The brand name of a synthetic form of the hormone oxytocin used to induce or augment labor.
Pituitary gland: A gland at the base of the brain that produces hormones, including those that trigger ovulation and stimulate milk production.
Placenta: A pancake-shaped organ that develops in the uterus. Connected to your baby via the umbilical cord, the placentadelivers nutrients and oxygen to your baby and removes waste.
Placenta accreta: When the placenta grows deeply into the uterine wall. This makes it difficult to fully remove and increases the risk of bleeding after the baby is delivered. Placenta accreta is rare and serious, but extra precautions during delivery can keep you and your baby safe.
Placental abruption: When the placenta begins to separate from the wall of the uterus before the baby is born. Symptoms of a placental abruption usually include bleeding and abdominal pain.
Placenta previa: When the placenta attaches low in the uterus, fully or partially covering the cervix. Placenta previa can cause bleeding during pregnancy and may prevent vaginal delivery.
Plasma protein A: A hormone produced by the fetus and passed into the mother's bloodstream. Levels of this hormone can be checked via a blood test during the first trimester. Low levels (combined with high levels of other hormones) can indicate an increased risk of the baby having Down syndrome.
Polycystic ovary syndrome (PCOS): A hormonal disorder in which ovarian follicles fail to mature properly, instead forming ovarian cysts. PCOS is often associated with infertility.
Polyhydramnios: Too much amniotic fluid in the uterus. Polyhydramnios usually resolves on its own, but it can sometimes cause pregnancy complications.
Postdural puncture headache: A severe headache can happen when the needle used for an epidural punctures the covering of the spinal cord, allowing spinal fluid to seep into the epidural space. Also called a spinal headache.
Postmature pregnancy: When a baby is born at 42 weeks or later.
Postnatal period: The time following delivery until 4 to 6 weeks after birth.
Postpartum: The first 6 weeks after delivery. The postpartum weeks are considered a recovery period for mom.
Postpartum depression (PPD): More severe than the more common baby blues, postpartum depression is characterized by crying, irritability, sleep problems, restlessness, feelings of hopelessness, and the inability to care for the baby. Professional treatment is often needed.
Postpartum hemorrhage: Heavy bleeding from the uterus after delivery. Postpartum hemorrhage usually occurs within a day of delivery, but it can happen up to 12 weeks postpartum.
Postpartum psychosis: Much rarer and more serious than postpartum depression, the symptoms of postpartum psychosisinclude loss of reality, hallucinations and/or delusions, as well as suicidal or aggressive thoughts. Professional treatment is needed immediately.
Postpartum thyroiditis: Fluctuating thyroid function after childbirth. Symptoms begin with hyperthyroidism and can include fatigue, irritability, increased sweating, and insomnia, followed by hypothyroidism, with its symptoms of depression, muscle aches, hair loss, dry skin, and poor memory.
Postterm pregnancy: A pregnancy that has lasted 42 weeks or more considered to be postterm, or overdue.
Precipitous birth: A very fast labor and delivery, usually lasting fewer than three hours. Read one mom's story of giving birth at home in under 2 hours.
Preeclampsia: A complication of pregnancy characterized by high blood pressure and protein in the urine after 20 weeks of pregnancy. Symptoms include rapid weight gain and increased swelling. If left untreated, preeclampsia can lead to the more serious eclampsia.
Pregnancy Discrimination Act: A federal law prohibiting discrimination against women for conditions related to pregnancy or childbirth.
Pregnancy-induced hypertension (PIH): High blood pressure that develops during pregnancy, usually in the third trimester.
Pregnancy test: A blood or urine test for pregnancy. The test works by detecting the pregnancy hormone hCG.
Premature baby: A baby born before week 37 of pregnancy is considered premature.
Premature labor: Labor that occurs between 20 and 37 weeks. Premature labor doesn't necessarily translate into an early delivery. Sometimes it stops on its own, and sometimes doctors can help delay the delivery, improving the baby's chances for survival.
Prelabor rupture of membranes (PROM): The breaking of the amniotic sac before contractions begin. Usually, labor starts soon after rupture. If it doesn't, depending on when PROM occurs, your practitioner may induce or augment labor.
Prenatal: Before birth.
Prenatal care: Medical care during pregnancy.
Presentation: See fetal presentation.
Presenting part: The part of the baby’s body that leads the way during labor and delivers first.
Preterm baby: See premature baby.
Preterm delivery: The birth of a baby before 37 weeks gestation.
Preterm labor: See premature labor.
Preterm prelabor rupture of membranes (PPROM): The bursting of the amniotic sac before 37 weeks gestation. See PROM.
Primigravida: A woman who is pregnant for the first time.
Primipara: A woman who has given birth once after 20 weeks gestation.
Prodromal labor: A type of false labor. Prodromal contractions can be painful, but they don’t get stronger or closer together, and they don’t cause the cervix to dilate.
Progesterone: A hormone produced by the ovaries that helps to regulate a woman's reproductive cycle. It also keeps the uterus from contracting during pregnancy and promotes the growth of the blood vessels in the uterus.
Prolactin: The hormone that activates milk production. While pregnant, prolactin levels rise and stay elevated if you’re breastfeeding.
Prolapsed cord: See cord prolapse.
Prolonged labor: A labor that lasts 18 to 24 hours.
Prolonged pregnancy: A pregnancy that lasts longer than 40 weeks.
Prostaglandins: Hormones produced by the uterus that help soften the cervix and bring on labor.
Proteinuria: When excess protein is found in the urine. It’s often a sign of preeclampsia.
Protracted labor: A labor that progresses more slowly than expected.
Pruritic urticarial papules and plaques of pregnancy (PUPPP): Small, itchy pimples that break out on stretch marks or nearby skin. PUPPP lesions aren't dangerous and generally disappear after delivery.
Pruritus gravidarum: Itching during pregnancy.
Pubic symphysis: The joint at the front of the pelvis. During pregnancy, your practitioner will use the pubic symphysis to measure uterine growth. Also called symphysis pubis.
Pubic symphysis dysfunction: Pain in the pubic symphysis during or after pregnancy. SPD is caused by a misalignment or widening of the pubic symphysis during or after pregnancy. Also called symphysis pubis dysfunction (SPD).
Pudendal block: A regional anesthetic injected into the perineal or vaginal area to reduce pain during delivery, often when forceps or vacuum extraction is used.
Puerperium: The span of time from the end of delivery until the uterus returns to its pre-pregnancy state, usually about 6 weeks.
Pyogenic granuloma of pregnancy: A lesion a pregnant woman may have on her gums. Pyogenic granuloma bleeds easily, but it’s harmless and goes away on its own after delivery.
Q
Quad screen: A prenatal blood test done between 15 and 22 weeks to check levels of four substances (AFP, hCG, estriol, and inhibin-A). The quad screen estimates your baby's risk for certain chromosomal abnormalities and neural tube defects. If results come back outside the expected range, your provider may recommend additional testing for reassurance.
Quickening: The first time you feel your baby move, usually between 18 and 22 weeks, though some moms feel it earlier (especially in later pregnancies). Quickening is often described as a fluttering, tiny taps, or butterflies in the belly.
“There are little bubble movements in my lower groin area and I know it's baby!” says one What to Expect Community mom.
R
Rectum: The lower part of the large intestine that ends at the anus.
Rectus abdominis: The central muscle that runs down the front of the abdomen (your “six-pack”). During pregnancy, these muscles may separate (a condition called diastasis recti). They usually come back together after birth, and gentle diastasis recti exercises can help encourage healing. See diastasis.
Recurrent miscarriage (recurrent pregnancy loss): See habitual miscarriage.
Reflexology: A complementary therapy in which pressure is applied to specific areas of the feet, hands, or ears to help ease a variety of aches and pains. Applying pressure to certain areas on or near the feet can trigger contractions, so it is best to avoid reflexology of the feet during pregnancy unless your provider gives the all-clear.
Regional anesthesia: Medication that numbs one area of the body during labor. An epidural is a regional anesthesia because it numbs only the lower part of the body while keeping you awake and alert.
Relaxin: A pregnancy hormone that softens and loosens your joints and ligaments, allowing your pelvis to expand during labor. Relaxin can also lead to temporary body changes, like feeling more flexible — or noticing your foot size increase a bit.
Restless legs syndrome (RLS): A surprisingly common condition affecting about one in four pregnant women. RLS causes tingling, crawling, or restless sensations in your legs or feet, making it hard to wind down at night. The exact cause is unknown, but the good news: it almost always disappears after delivery.
Retained placenta: A placenta that remains in the uterus for 30 minutes or more after birth. If you have a retained placenta, your practitioner may gently remove it to prevent bleeding or infection.
Retroverted uterus: In 20 percent of women, the top of the uterus is tilted toward the back instead of the front. In most cases, the uterus rights itself by the end of the first trimester and doesn’t cause any issues. Also called a tilted uterus or a tipped uterus.
Retrovir (AZT): An antiretroviral medication used to treat HIV-positive pregnant women, helping reduce the chance of passing the virus to the baby. See AZT, zidovudine.
Rh factor: A protein found on red blood cells. If you have it, you're Rh-positive. If not, you’re Rh-negative. An Rh-negative mom carrying an Rh-positive baby may produce antibodies against the baby's blood. Your initial prenatal blood work will include Rh factor screening.
Rh immunoglobulin: A medication that prevents an Rh-negative mom from producing antibodies that could attack an Rh-positive baby's blood cells. It's typically given at 28 weeks and again after birth if the baby is Rh-positive. Also called RhoGAM, Rhlg.
Rh incompatibility: A difference between the mother's and baby's Rh factors that can cause complications if untreated. With monitoring and RhoGAM, most women deliver healthy, full-term babies.
RhoGAM (RhIg): See Rh immunoglobulin.
Ripening: See effacement.
Rooming-in: When your baby stays in your hospital room rather than the nursery.
Rooting: A newborn reflex: When you stroke your baby's cheek, he'll open his mouth and turn his head to nurse.
“Baby rooting is the most adorable thing,” says What to Expect Community mom Jlw8t7. “I love her little rooting face when I go to breastfeed her.”
Round ligament pain: A common pregnancy discomfort — sharp or achy pains low in the belly or groin as the ligaments supporting your growing uterus stretch. Round ligament pain often starts around 14 weeks, but it can happen any time after the first trimester.
Rubella: Also known German measles, rubella is a highly contagious viral infection that can cause serious complications in pregnancy. Women who haven't had it should make sure they're immunized before conception.
Rupture of membranes: When your amniotic sac breaks (your water breaks). It's a sign that labor will begin soon or has already started.
S
Saddle block: A regional anesthesia injected into the fluid surrounding the spinal cord. It's often used for pain relief during a forceps or vacuum-assisted delivery.
Scan: Another word for ultrasound exam. The 20-week anatomy scan is a detailed look at your baby’s growth, organs, placenta, and amniotic fluid.
Sciatica: A sharp, shooting, or burning pain in lower back, buttocks, or legs. In pregnant women, sciatica is often caused by pressure of the enlarging uterus on the sciatic nerve. Rest, CAM therapies, or a heating pad may ease the pain.
Sciatic nerve: The largest nerve in the body, running from the lower back through the buttocks and down the leg. It controls movement and sensation in the legs.
Sea bands: Elastic wristbands that put pressure on acupressure points on the inner wrists. Many moms-to-be use them for easing morning sickness.
Secondary infertility: Difficult getting pregnant or carrying a pregnancy to term after already having had a child. Secondary infertility is more common than first-time infertility.
Secondhand smoke: Smoke that's breathed in from someone else's cigarette. Secondhand smoke, like smoking, can be harmful to a developing baby.
Selective serotonin reuptake inhibitors (SSRI): A class of antidepressant medications often given to mothers suffering from postpartum depression or depression during pregnancy.
Semen: White fluid containing sperm ejaculated from a man's penis.
Sexually transmitted disease (STD): Infections that can be passed through sexual contact, including chlamydia, gonorrhea, syphilis, trichomoniasis, HIV, hepatitis B, and HPV. Some STDs can affect pregnancy, but most are treatable.
Shoulder dystocia: When a baby's shoulders get stuck in the birth canal after the head has been delivered. Shoulder dystocia is uncommon, and providers are trained to handle it safely with special maneuvers.
Show: See bloody show.
Sickle-cell anemia: A genetic disorder that cause red blood cells to form a sickle shape. Sickle-cell anemia is most common among people of African descent.
Side-lying position: A breastfeeding position where you and your baby lie on your sides facing each other. This position is especially helpful during nighttime feedings or post-cesarean recovery.
SIDS: Abbreviation. See sudden infant death syndrome.
Sitz bath: A shallow, tepid bath used to soothe discomfort from episiotomy stitches, swelling, or soreness after delivery. You can purchase a basin that sits on a toilet seat, or you can put a few inches of water in your bathtub to create your own sitz bath.
“I lived for my sitz bath,” says What to Expect Community mom 22momma25. “I took like 3 a day for the first two weeks . . . The toilet basin makes it a lot easier to do quick ones . . . especially if you do them multiple times a day.”
Sleep apnea: When breathing stops briefly during sleep, temporarily reducing the amount of oxygen that's taken in. Pregnant women have a higher risk of sleep apnea, especially in the third trimester.
Small for gestational age (SGA): A baby who's smaller than expected for his gestational age. Unlike premature babies, SGA babies are small because of slow development, not because they've had less time in the womb.
Sonogram: An ultrasound image of a baby. Sonograms are performed with an ultrasound machine. Practitioners will often give expectant parents paper copies of their sonogram images to take home.
Sonographer: The technician who performs your ultrasound examination.
Sore nipples: Tender, red, cracked, or painful nipples caused by breastfeeding. A good latch, positioning tweaks, and soothing treatments can help relieve and prevent sore nipples.
Speculum: A medical instrument used to spread the vaginal walls so the provider can view the cervix. It's used during pelvic exams and Pap smears.
Sperm: The male reproductive cells produced by the testicles. Sperm fertilizes an egg to produce an embryo.
Spermicides: Chemical agents that kill sperm. Spermicides are often used along with condoms or other birth control methods.
Sperm motility: The ability of sperm to swim well — an important factor in fertility.
Spider veins: Small red or blue veins close to the skin’s surface that may appear during pregnancy thanks to hormones and increased blood flow. Spider veins usually fade after delivery.
Spina bifida: A neural tube defect in which the fetal spine doesn't close properly. Taking folic acid before conception and during pregnancy helps reduce the risk of spina bifida.
Spinal block: An injection of anesthesia into the fluid surrounding the spinal cord to provide fast, complete pain relief during labor or cesarean birth.
Spinal headache: See postdural puncture headache.
Spontaneous labor: Labor that begins on its own — contractions start, the cervix dilates and thins, and labor progresses without any medical augmentation.
Spontaneous miscarriage: See miscarriage.
Spotting: Light vaginal bleeding. Some spotting is normal during pregnancy, but always let your provider know.
Squat bar: A U-shaped bar attached to a birthing bed that helps a laboring woman squat while pushing.
Stages of labor: There are three stages of labor:
- Begins with the onset of contractions. The cervix dilates from 0 to 10 centimeters.
- Delivery of the baby.
- Delivery of the placenta.
Station: A measurement of how far the baby has descended into the pelvis. Zero station means your baby is engaged. Negative numbers from -1 to -5) mean your baby is still high, and positive numbers (+1 to +5) indicate progress toward crowning.
Steroids: Medications given to woman in preterm labor to help mature the baby's lungs more quickly.
Stillbirth: The loss of a baby after 20 weeks of pregnancy but before birth.
Stillborn: A baby born with no signs of life. Complications such as infection, problems with the placenta or umbilical cord, high blood pressure, and other conditions may be to blame. But sometimes no specific cause of a baby being stillborn is identified.
Stress incontinence: A type of urinary incontinence that results from the mounting pressure of the growing uterus on the bladder. Many women find they leak urine during the last trimester when they laugh, cough, or sneeze. Some women also experience postpartum urinary incontinence as a result of the stretching of the perineal muscles. Kegel exercises can help strengthen the muscles.
Stretch marks: Pink, red, or purplish streaks that appear as the skin stretches. During pregnancy, stretch marks, also known as striae, may appear on the abdomen, breasts, buttocks, and legs. They usually fade slowly after delivery.
Striae: See stretch marks.
Stripping of the membranes: A technique used to encourage the onset of labor. The practitioner inserts a finger between the membranes and the wall of the uterus to loosen the membranes from the wall. Also called sweeping of the membranes.
Suckling: What a baby does while breastfeeding — drawing milk from the breast.
Sudden infant death syndrome (SIDS): The sudden, unexplained death of an infant from unexplained causes. SIDS occurs most frequently in infants two to four months old. Safe sleep practices significantly reduce the risk.
Sweeping of the membranes: See stripping of the membranes.
Symphysis pubis dysfunction (SPD): See pubic symphysis dysfunction.
Symphysis pubis: See pubic symphysis.
Syphilis: A sexually transmitted infection that can cross the placenta. Syphilis can potentially cause birth defects, preterm birth, and stillbirth. Routine screening during pregnancy helps catch and treat it early.
Systolic blood pressure: The top number in a blood pressure reading, representing the amount of pressure when the heart is contracted.
T
Tay-Sachs disease: A rare inherited disorder (most common among people of Ashkenazi Jewish descent) in which a baby is born without an essential enzyme. Sadly, Tay-Sachs is fatal in early childhood. A preconception test can determine whether potential parents carry the disease.
TENS: Abbreviation. See transcutaneous electrical nerve stimulation.
Teratogen: A drug, chemical, or infection that can cause a birth defect when a woman is exposed to it during pregnancy.
Terbutaline: A medication used to help stop contractions during preterm labor.
Term: A full-length pregnancy, 40 weeks.
Termination: See abortion.
Thalassemia: A group of inherited blood disorders that affect hemoglobin. Thalassemia is more common in people of Mediterranean, Black, or Southeast Asian ancestry.
Threatened miscarriage: Anytime there’s vaginal bleeding during the first half of pregnancy, the pregnancy is considered threatened. Your provider may do an exam and tests to look for the cause and determine if treatment is needed.
Thrombophlebitis: Inflammation of a vein caused by a blood clot. The risk of thrombophlebitis rises in pregnancy.
Thyroiditis: Inflammation of the thyroid gland, most often postpartum. Symptoms begin with hyperthyroidism and can include irritability, increased sweating, and insomnia and later shift into hypothyroidism, with fatigue, depression, muscle aches, dry skin, hair changes, and poor memory.
Tilted uterus: See retroverted uterus.
Tipped uterus: See retroverted uterus.
Tocolysis: Using medications to stop uterine contractions during premature labor.
Toxemia: An older term for preeclampsia.
Toxoplasmosis: A parasitic infection found in cat feces and undercooked meat. Toxoplasmosis can be harmful to a fetus, which is why pregnant women are advised to avoid handling cat litter and to fully cook meat.
Transcutaneous electrical nerve stimulation (TENS): A complementary therapy used to relieve labor pains. Electrodes placed on the back send small electrical pulses along nerve pathways leading to the uterus and cervix, crowding out pain signals. Laboring moms can control the intensity of the stimulation.
Transducer: The handheld device used during an ultrasound to send sound waves to a computer, resulting in an ultrasound image of your baby.
Transitional labor: The end of the first stage of labor, when the cervix dilates from eight to 10 centimeters. Transition is the most demanding stage of labor because the contractions are very strong, very close together, and very long. Fortunately, the transition stage is also usually the shortest.
Transverse: When the baby is turned sideways in the uterus instead of head-down.
Trial of labor after cesarean delivery (TOLAC): Attempting a vaginal birth after having a prior C-section. If successful, it results in a VBAC (vaginal birth after cesarean).
Trimester: A three-month stretch of pregnancy. Pregnancy is divided into three trimesters, each approximately 13 to 14 weeks and marked by different stages of fetal development.
Triple screen: A blood test done between 15 and 20 weeks of pregnancy to screen for an increased risk of the baby having a birth defect. High alpha-fetoprotein (AFP) levels may point to a neural tube defect, while low AFP levels suggest a higher risk of Down syndrome. The triple screen is used to decide whether more invasive testing, such as an amniocentesis, is needed.
Trophoblastic disease: A rare abnormal pregnancy in which there is no fetus, only an abnormal mass of tissue.
Tubal ligation: A sterilization procedure — also called tubal sterilization or “getting your tubes tied.” Tubal ligation means a woman's fallopian tubes are cut, tied off, or blocked, to prevent pregnancy.
Tubal pregnancy: See ectopic pregnancy.
U
Ultrasound: A test that uses high-frequency sound waves to create a moving image of your baby in the womb. During pregnancy, ultrasounds are routinely used to check on your baby's growth, development, and overall well-being.
Umbilical artery Doppler velocimetry: A specialized ultrasounds that looks at how blood is flowing through the umbilical artery. Weak, absent, or reversed flow can signal that the baby isn't getting adequate nourishment.
Umbilical cord: See cord.
Umbilical cord blood banking: See cord blood banking.
Undescended testicles: When a baby boy's testicles don't descend into the scrotum by the time he's born. The condition often corrects itself but sometimes needs to be surgically corrected.
Unripe cervix: A cervix that isn't ready for delivery. Usually, as the end of pregnancy approaches, the cervix moves forward in the pelvis and begin to soften. If the cervix doesn't soften on its own, prostaglandins may be used to help to ripen it — for an induction, for example.
Urge to push: The strong, natural impulse to bear down and push the baby out. Your provider will guide you and won't have you push until you're fully dilated.
Urinalysis: A simple urine test used to check for things like protein, sugar, and signs of infection. You'll have urine testsroutinely during pregnancy.
Urinary incontinence: See stress incontinence.
Urinary tract infection (UTI): An infection anywhere in the urinary system, most often the bladder. Symptoms may include fever, increased need to urinate, or a burning sensation while urinating. UTIs are common during pregnancy and are treated with antibiotics.
Uterine inversion: A rare complication in which the top of the uterus turns inside out — usually because the placenta hasn't fully detached. In most cases of uterine inversion, the uterus can be pushed back into place by hand. If not, surgery is needed.
Uterine involution: The postpartum process of the uterus returning to its normal size after the birth of a baby. Your postpartum nurse may massage your belly (fundal massage) to help the process.
Uterine rupture: A tear in the uterus, most often at the site of a previous C-section scar. Symptoms of a uterine rupture may include sudden, searing pain in the abdomen and signs of fetal distress. Immediate cesarean delivery is necessary, followed by repair of the uterus, if possible.
Uterus: The hollow, pear-shaped, muscular organ where your baby grows throughout pregnancy. Also called the womb.
V
Vacuum-assisted birth: A type of assisted delivery in which a plastic cup is applied to the baby's head and gentle suction helps ease the baby out of the birth canal. Also known as vacuum-assisted delivery.
Vagina: The muscular birth canal that extends from the cervix to the external genital opening between the labia.
Vaginal birth: The birth of a baby through the birth canal. About two-thirds of moms give birth vaginally. A vaginal birth is different from a cesarean birth, which is the birth of a baby through a surgical incision in the abdomen and uterus.
Vaginal birth after cesarean (VBAC): The vaginal birth of a baby after a previous cesarean birth. The American College of Obstetricians and Gynecologists supports the use of VBAC over repeated C-section when women meet specific safety criteria.
Vaginitis: An infection or inflammation of the vagina. Symptoms may include itching, burning, soreness, or green/yellow/strong-smelling discharge.
Varicose veins: Swollen, enlarged veins, usually in the legs, that become more noticeable in pregnancy due to increased blood volume and pressure from the growing uterus. Varicose veins often fade after delivery.
VBAC: Abbreviation. See vaginal birth after cesarean.
Venous thrombosis: A blood clot in a vein, usually in the leg. Pregnancy and the postpartum period increase the risk for developing blood clots.
Vernix caseosa: The creamy white, cheese-like coating on a newborn’s skin. The vernix caseosa protects the fetus from the amniotic fluid in the womb — and makes the baby slippery at birth!
Version: See external cephalic version.
Vertex presentation: When a baby is positioned head-down in the uterus — the ideal position for birth.
Very low birth weight baby: A baby weighing less than 3 pounds 3 ounces at birth.
Viable: A baby mature enough to survive outside the womb with medical support.
Vibroacoustic stimulation (VAS): See fetal acoustic stimulation.
Vulva: A woman's external genital organs, including the labia and clitoris.
W
Walking epidural: A type of epidural that numbs pain but allows enough leg sensation for some movement — even standing or walking with support.
Water birth: A birth in which a woman labors and/or gives birth in tub or pool of warm water. If you choose to have a water birth, experts recommend laboring in water but delivering outside the tub for safety.
Womb: See uterus.
Y
Yeast infection: A vaginal infection common during pregnancy. Symptoms of a yeast infection include itching and a white, strong-smelling discharge from the vagina.
Z
Zidovudine (ZDV): An antiretroviral drug used to reduce HIV transmission from an HIV-positive expectant mother to her baby. See AZT, Retrovir.
Zygote: The fertilized egg before it begins to divide and develop into an embryo.
Yes 
No 
