Written by:

Dr Diane Farrar

RM, BSc health science, BSc psychology, PhD reproductive endocrinology

Dr Diane Farrar is a practising midwife with over 25 years’ experience. She is a senior research fellow at the Bradford Institute for Health Research and visiting associate professor at the University of Leeds. Her research, which includes the areas of diabetes, high blood pressure, obesity and memory function, has been published in leading medical journals.

HELLP Syndrome

In this article:

  • What is HELLP Syndrome?
  • What causes HELLP Syndrome?
  • What are the symptoms of HELLP Syndrome?
  • How is HELLP Syndrome diagnosed?
  • What are the risks of HELLP syndrome?
  • How may HELLP syndrome affect my baby?
  • How will HELLP syndrome be managed and treated?
  • How can HELLP syndrome be prevented?
  • Is it likely I'll get HELP Syndrome again in a future pregnancy?
  • Main Points

HELLP Syndrome

What is HELLP Syndrome?

HELLP syndrome is a rare condition, affecting less than 1% of pregnancies, usually after 27 weeks gestation, although about a third of women develop this condition shortly after childbirth. HELLP is named after three of the main features of the disease (haemolysis (breakdown of red blood cells), elevated liver enzyme levels, and low platelet levels).

What causes HELLP Syndrome?

Although HELLP syndrome is rare, it is a life-threatening condition, the causes of which are unclear. HELLP normally develops in women who have severe pre-eclampsia, though around one to two in ten women who develop HELLP will not have a diagnosis of pre-eclampsia. Pre-eclampsia is a condition of pregnancy where blood pressure is increased and protein is excreted in urine. The causes of pre-eclampsia are believed to be due to abnormal placental development early in pregnancy. Perhaps as a consequence of the abnormal placental development and other physiological changes that occur with pre-eclampsia, some women go on to develop HELLP syndrome.

What are the symptoms of HELLP Syndrome?

It is important to remember that HELLP syndrome is rare; even so if you know you have high blood pressure or pre-eclampsia, you should inform your doctor or midwife if you feel generally unwell. Women who have HELLP may feel sick and vomit, and they could have stomach pain on the upper right side (over the area of the liver). These symptoms can seem unspecific and may be put down to a virus. Around half of affected women will have a headache and visual disturbance. Quick and excessive weight gain can happen, due to water retention called oedema, and symptoms may increase at night. If you experience some or all of these symptoms, even if you don’t know you have high blood pressure or pre-eclampsia, you should contact your doctor or midwife, because early treatment lowers complication rates and recovery is likely to be quicker.

How is HELLP Syndrome diagnosed?

For HELLP syndrome to be diagnosed, there must be abnormal red blood cell breakdown, low platelet levels, and abnormal liver function. There are different criteria for diagnosing HELLP syndrome and measuring the severity of the condition; however, it is unclear which criteria is best. The different criteria use blood levels of certain biochemical markers to help assess the severity. Below are two common criteria:

The Mississippi HELLP Classification System categorises women based on their lowest platelet count (platelets are needed for blood to clot effectively):

  • Class one HELLP syndrome ‐ platelets less than or equal to 50,000 cells per cubic millimetre (cells/mm³)
  • Class two HELLP syndrome ‐ platelets less than or equal to 100,000 cells/mm³
  • Class three HELLP syndrome ‐ platelets less than or equal to 150,000 cells/mm³.

Tennessee Classification System suggests strict criteria for “true” or “complete” HELLP syndrome. Abnormal red blood cell breakdown is diagnosed by abnormal peripheral blood smear (number and shape of red and white cells and platelets), increased serum bilirubin (bilirubin is released when red blood cells are broken down) and elevated lactate dehydrogenase (which signifies cell damage) levels.

What are the risks of HELLP syndrome?

The high blood pressure that is often present when HELLP syndrome develops can lead to bleeding in the brain of some women; this is the most severe, but thankfully rarest, complication. Kidney and liver problems may develop and spontaneous bleeding can happen which is caused by the abnormal changes to blood clotting processes. Women with HELLP syndrome are also at risk of having a stroke and sepsis (sepsis is a severe form of infection).

How may HELLP syndrome affect my baby?

HELLP syndrome that develops during pregnancy puts the unborn baby at risk if placental function is affected. Because the treatment of HELLP symptoms is only successful once the baby is born, it’s also likely the baby will need to be born prematurely. The degree and type of problems a baby born to a mother with HELLP syndrome will have mostly depends on the severity of the condition and the degree of prematurity. It’s best for babies to be born at full term; however, HELLP syndrome and its complications put the woman’s life at risk and also her baby’s, so the only option may be to deliver the baby early.

How will HELLP syndrome be managed and treated?

Treatment of HELLP starts with an assessment of the severity of the condition and stabilisation of the mother. Drugs will be given to bring down high blood pressure and prevent seizures. Seizures (or fits) can occur with pre-eclampsia when blood pressure is very high. Corticosteroids are often given to help improve platelet count and blood clotting. Other drugs will be given to treat the abnormal biochemical marker levels and to try and prevent damage to maternal organs. Once the woman’s condition is stabilised, speedy delivery of the baby, often by Caesarean section, is a priority.

How can HELLP syndrome be prevented?

Unfortunately, because the cause of HELLP is unclear, there is currently no way to prevent it. However being in the best health before pregnancy gives the best chance of having a healthy pregnancy and a healthy baby.

Some women are more at risk of developing pre-eclampsia (and therefore HELLP) than others because of certain risk factors. For example, they may have cardiovascular disease, be very young or aged 35 years or older, be overweight or obese, have had pre-eclampsia and HELLP in a previous pregnancy or have a mother who suffered from pre-eclampsia. These women may be prescribed low dose aspirin which reduces the risk of pre-eclampsia.

Is it likely I’ll get HELP Syndrome again in a future pregnancy?

One out of every four or five women that develop HELLP will go on to develop the condition again in a future pregnancy. Because of this increased risk of recurrence, it is important that women who have had HELLP plan future pregnancies and seek health advice before becoming pregnant and obtain maternity care as soon as they are aware they are pregnant.

If you are worried about HELLP and are planning to become pregnant you can speak with your GP. If you are pregnant and have any symptoms that are linked to HELLP syndrome you should contact your doctor or midwife immediately, because early recognition and treatment can help prevent the syndrome becoming severe.

Main Points

  • HELLP syndrome is a rare complication, affecting less than 1% of pregnancies. Though rare, it is a serious, life-threatening condition.
  • HELLP syndrome usually develops in women with severe Pre-eclampsia, though some women will develop it without a diagnosis of pre-eclampsia.
  • Women who have HELLP may feel sick and vomit, and they could have stomach pain on the upper right side (over the area of the liver). Around half of affected women will have a headache and visual disturbance. It’s important to contact your doctor or midwife if you notice these symptoms.
  • For HELLP syndrome to be diagnosed, there must be abnormal red blood cell breakdown, low platelet levels, and abnormal liver function.
  • There are several severe complications associated with HELLP syndrome, which is why it’s treated as a medical emergency.
  • If placental function is affected, your baby could be at risk.
  • If you develop HELLP syndrome, the risk of complications may mean you have to deliver your baby early.
  • Because the causes of HELLP are unclear, there is currently no way of preventing it.
  • The only way to cure the condition is by giving birth, which means, after the mother Labour may need to be induced. It’s advisable to be in the best health before pregnancy, which means sticking to a healthy diet.
  • The risk factors of pre-eclampsia, including cardiovascular disease and obesity, also apply to HELLP syndrome. Medical professionals may advise women at risk of pre-eclampsia to take steps to reduce their risk.