HELLP syndrome is a rare but serious pregnancy complication that affects the blood and liver, and it’s often linked to preeclampsia, or pregnancy-related high blood pressure. While HELLP can come on quickly — usually in the third trimester — prompt treatment can help protect both you and your baby. Knowing the warning signs can make all the difference.

Fortnuately, HELLP syndrome is rare, occurring in about 1 or 2 in 1,000 pregnancies. Among women with severe preeclampsia or eclampsia, the number is higher, appearing in 10 to 20% of pregnancies.[1]

If you develop HELLP syndrome during your pregnancy, you’ll need to get treatment right away. Here are some symptoms to look out for — plus when to call your doctor.

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Key Takeaways
  • HELLP syndrome is a rare but serious pregnancy complication that affects the blood and liver, and is often linked to preeclampsia.
  • Common symptoms include upper abdominal pain, nausea, headaches, blurry vision, swelling, and feeling generally unwell.
  • If something feels off — especially in the third trimester — call your health care provider right away.
  • Treatment usually involves delivering the baby, sometimes early, to protect both mom and baby from potentially dangerous complications.

What is HELLP syndrome?

HELLP syndrome is a rare pregnancy complication that affects the liver and blood. HELLP stands for:[2]

  • Hemolysis (H), where your red blood cells are broken down too soon, causing dangerously low red-cell blood counts.
  • Elevated liver enzymes (EL), which indicate that some of the cells of the liver are injured and releasing enzymes.
  • Low platelet count (LP), which makes proper blood-clotting difficult and could cause increased bleeding during labor.

It's a more serious form of preeclampsia, though some experts consider HELLP syndrome a different condition.

What are the symptoms of HELLP syndrome?

HELLP typically occurs during the third trimester, although some cases develop in the week after delivery. Possible symptoms include:

  • Pain and tenderness in the upper right side of the abdomen
  • Nausea and vomiting that worsens
  • Headaches
  • Blurry vision
  • General malaise
  • Nosebleeds (in rare cases)
  • Quick weight gain or swelling
  • Seizures (in rare cases)

"I had pain on my right side right underneath my ribs and also in my lower back," says What to Expect Community member laurenep10.

It can be easy to confuse some of these symptoms with the common complaints of a normal pregnancy. Sometimes, HELLP syndrome can even be misdiagnosed as the flu, hepatitis, or gallbladder disease.

"Most of my symptoms weren't something I would know without labs and scans," says Community mom AWeeks323. "... I was so outwardly 'normal' that the nurses told me that I was just experiencing normal pregnancy symptoms until they got my labs back."

Those third-trimester symptoms can blur together sometimes — from everyday aches to signs that deserve a closer look. Download the What to Expect app to track symptoms, follow your baby’s growth week by week, and know when it’s time to call your health care provider.

Let your health care provider know if you notice any of these changes, or if you simply don’t feel right — especially if you have or are at risk of preeclampsia. If your doctor isn’t available, head to the local emergency room right away.

What causes HELLP syndrome?

Experts don't fully understand what causes HELLP syndrome. However, you’re at greater risk if you have preeclampsia — pregnancy-related high blood pressure coupled with protein in the urine — or eclampsia, a very serious condition accompanied by seizures that can evolve if preeclampsia is left untreated.

Other risk factors for developing HELLP syndrome include:

  • A history of preeclampsia or HELLP syndrome
  • A history of kidney disease, diabetes, or high blood pressure
  • Previous pregnancies and births
  • Being older than 35

How is HELLP syndrome diagnosed?

In many cases, women are diagnosed with preeclampsia before being diagnosed with HELLP. If your doctor suspects that you have HELLP, you'll have a physical exam to check for:

  • Abdominal soreness (especially in the upper right side)
  • Swelling in your legs
  • An enlarged liver
  • High blood pressure

Your practitioner will also likely do a blood test to check your liver enzymes (which may be high) and a complete blood count, which would show low platelets and lower red blood cells. You may also have a non-stress test, which monitors your baby’s heart rate, as well as an ultrasound to see how your baby is doing.

What are the possible complications of HELLP syndrome?

HELLP syndrome can threaten both your life and that of your baby if it’s not diagnosed and treated quickly. Some of the complications linked to HELLP include:

  • Bleeding and blood clotting problems
  • A buildup of fluid in the lungs (pulmonary edema), which can cause difficulty breathing
  • Extensive liver damage or liver failure
  • Stroke
  • Kidney failure
  • Placenta abruption, in which the placenta tears away from the uterine wall, causing severe blood loss that often requires a blood transfusion

Fortunately, most complications will improve once your baby is delivered and you have time to recover.

If HELLP is diagnosed before your pregnancy reaches full term, your baby will be delivered early and may require monitoring for complications related to prematurity, including lungs that aren’t fully developed.

How is HELLP syndrome treated?

The main treatment for HELLP syndrome is delivery of your baby, even if she’s born prematurely. That’s because the complications of HELLP can cause problems for both you and your baby.

If you develop HELLP when you’re at least 34 weeks pregnant, your health care provider will likely want to deliver your baby right away, before the condition progresses and presents further risks. 

Vaginal delivery is most common, if possible, as blood-clotting issues associated with HELLP can complicate a C-section.

If baby’s lungs aren’t yet mature, you may receive corticosteroids to speed up their maturity before delivery.

If you develop HELLP earlier in your pregnancy, your practitioner may attempt to delay delivery until your baby has more time to develop. You’d most likely be kept under observation in the hospital. Your doctor may also give you:

  • Blood pressure medication to treat high blood pressure
  • Magnesium sulfate to prevent seizures

How can you prevent HELLP syndrome?

There is no known way to prevent HELLP, so it's recommended you do all the usual things to have a healthy pregnancy:

  • Go to all of your prenatal appointments
  • Take your prenatal vitamin
  • Eat a balanced, nutritious diet
  • Exercise regularly
  • Try to get enough sleep

If you have a history of preeclampsia, your practitioners may prescribe low-dose aspirin to lower your chance of getting it again. And if you experienced HELLP in a previous pregnancy, be sure to let your doctor know.

It's also important to let your practitioner know right away if you experience any of the above signs of HELLP or preeclampsia. 

HELLP syndrome can feel scary, especially because some symptoms can mimic typical pregnancy discomforts. But trusting your instincts and getting care quickly can make a big difference for both you and your baby — and help ensure you get the support and treatment you need every step of the way.