HELLP Syndrome

Preeclampsia is sometimes complicated by a constellation of symptoms and signs called the HELLP (H = Hemolysis, EL = Elevated Liver enzymes, LP = Low Platelets) syndrome.

Both complete and incomplete forms are known, with all three major components, or with only one or two, respectively. It carries serious risk for both the pregnant woman and the baby, and it is important to achieve timely delivery in the right way to attain the best possible outcome.

Incidence

The HELLP syndrome complicates 0.5-9% of all pregnancies, but the rate is much higher (10-20%) in cases with preeclampsia. It typically occurs between week 27 and 37 of pregnancy, but in a third of cases it is earlier or later than this. It may occur after delivery, usually within 48 hours.

Clinical Features

The HELLP syndrome is of rapid onset, but in over half of all patients it is heralded by generalized swelling and excessive increase in weight.

The symptoms include pain in the right upper or upper central part of the abdomen, with nausea and vomiting. Other symptoms include headache, visual complaints or feelings of malaise.

Laboratory investigations reveal broken up red blood cells because of trauma incurred as they pass through damaged blood vessels. This is associated with reduced hemoglobin, increased bilirubin (leading eventually to jaundice), and high liver enzymes. Platelet counts fall because of their consumption by numerous small clots within the damaged blood vessels.

Diagnosis and Management

The Sibai criteria call for an abnormal peripheral blood smear showing the presence of hemolysis within the blood vessels, increased serum bilirubin and high LDH levels, to diagnose HELLP syndrome.

Complications

The complications of the HELLP syndrome include:

• abruptio placentae (separation of the placenta from the uterine wall before the baby is born)
• disseminated intravascular coagulation (DIC) with the consumption of all available platelets and clotting factors by numerous microthrombi within the blood vessels of the body, which leads to potentially deadly uterine bleeding
• rarely, rupture of a liver hematoma
• liver and renal failure
• pulmonary edema (fluid collection inside the lungs)
• retinal detachment
• stroke

Mortality rates vary from 1-25% depending upon the case severity and type of care. Between 7 and 34% of babies die in the period surrounding their birth, especially if born before 32 weeks. Surviving infants have a higher risk of neurological damage due to cerebral hemorrhage and birth asphyxia, probably due to the premature delivery and low birth weight.

Women with HELLP syndrome may be prepared for immediate delivery provided the baby is at least 34 weeks. If between 27-34 weeks, the mother is evaluated, and supportive care is given. This includes intravenous fluids, drugs to lower the blood pressure if elevated, and magnesium sulfate to reduce the risk of convulsions (eclampsia). Steroids are administered to help the baby achieve lung maturity, and elective delivery is planned within 48 hours of diagnosis.

In very early pregnancies (before 27 weeks), the mother may be observed for as long as possible, with corticosteroids often being given during this interval, but it is usually wise to induce labor in the interests of the mother if HELLP occurs before 24 weeks.

Other drugs used for treatment of HELLP syndrome include:

• antithrombin which antagonizes the bleeding tendency and improves fetal growth and health
• S-nitrosoglutathione to lower the arterial pressure while keeping uterine flow to the baby normal

A C-section is always required if a liver hematoma breaks open, along with packing or lobectomy of the liver, tying off the artery, introducing a foreign blocking material (embolus) into the torn artery, or liver transplantation in rare cases. Magnesium sulfate helps prevent eclampsia and protects against cerebral palsy in the newborn to some extent.

Following delivery, the mother needs to have continued monitoring as the platelet counts keep going down for a few days, and the chances of renal failure and lung edema go up after delivery. Various blood products may be given as part of supportive care, with intravenous fluid to ward off a reduced urine output. Women with HELLP syndrome at 28 weeks or less are more likely than others to have preterm birth, preeclampsia, and to have their babies die in the newborn period.

Sources

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2654858/
• https://www.ncbi.nlm.nih.gov/pubmed/11031696
• https://rarediseases.info.nih.gov/diseases/8528/hellp-syndrome
• https://www.ncbi.nlm.nih.gov/pubmed/20491358
• https://www.ncbi.nlm.nih.gov/pubmed/23107053