MD Notes

creation date: 2025-07-21 19:05
tags: Pathologies

Hemolysis, Elevated Liver Enzymes, and Low Platelet Count Syndrome

Background

Definitions

HELLP is an acronym that refers to a syndrome in pregnant and postpartum patients characterized by hemolysis, elevated liver enzymes, and a low platelet count.

It is hypothesized to be a severe form of preeclampsia and occurs in 0.1% of normotensive pregnancies and 1% of preeclampsic pregnancies.

This condition is part of a group of disorders known as hypertensive disorders of pregnancy, which consist of:

These conditions presents a significant risk of morbidity to both mother and fetus, with the primary concern being the progression to preeclampsia/eclampsia and HELLP syndrome.

Etiology and Pathogenesis

The cause and pathogenesis of HELLP is unclear. If it is a severe form of preeclampsia, then its pathophysiology is likely the same. It may also share common pathways but deviate and cause more significant hepatic inflammation and coagulation activation than preeclampsia.

Ischemic-reperfusion injury at the spiral arteries is thought to trigger the systemic inflammatory process which leads to release of antiangiogenic factors and thus multiorgan microvascular injury. Injury of the liver leads to the laboratory findings.

Damaged vessel endothelium results in adhesion of platelets and thus thrombocytopenia. Red blood cells passing platelet-fibrin-rich capillaries break down resulting in microangiopathic hemolytic anemia.

Clinical Presentation

Signs & Symptoms

Typical symptoms include:

  • Upper abdominal pain that is tender to palpation, severe, and usually constant (but may be colicky)
  • Nausea, vomiting
  • Generalized malaise

Signs include:

  • Hypertension and proteinuria (85% of patients)
  • Thrombocytopenia-related bleeding (very rare, unusual)

Complicated/severe presentations include:

  • Hepatic bleeding
  • Eclampsia
  • Placental abruption (and possibly DIC)
  • Acute kidney injury
  • Pulmonary edema
  • Retinal detachment

History & Physical Exam

Symptoms typically develop between 28-37 weeks of gestation but late second trimester or at term/postpartum is also common.

Risk factors

  • Previous history of HELLP
  • Genetic predisposition (rare)

Diagnosis

Criteria

Diagnosis of HELLP syndrome is based on presence of all laboratory abnormalities within its name as described by the Tennessee criteria:

  • Hemolysis with a microangiopathic blood smear, as established by 2 of the following:
    • Peripheral smear with schisotocytes and burr cells
    • Serum bilirubin ≥20 mcmol/L
    • Low serum haptoglobin or LDH ≥2x ULN
    • Severe anemia unrelated to blood loss
  • Elevated liver enzymes (AST or ALT ≥2x ULN)
  • Low platelets (<100,000 cells/mcL)

The ACOG criteria requires LDH ≥600 IU/L to demonstrate hemolysis.

Work-up

Initial workup
In pregnant individuals with characteristics symptoms and signs and/or with new-onset hypertension in the 2nd half of pregnancy or postpartum, the following are tested to rule out HELLP:

  • CBC
  • Peripheral smear
  • AST, ALT, bilirubin
  • Creatinine
  • LDH (if using criteria that requires it)

Differential

The major disorders to differentiate are:

  • Acute fatty liver of pregnancy (AFLP)
  • Thrombotic thrombocytopenic purpura (TTP)
  • Pregnancy-related complement-mediated thrombotic microangiopathy (CM-TMA)
  • Systemic lupus erythematosus

The findings of HELLP may also overlap with preeclampsia with severe features.

Red Flags / Complications

While outcomes are generally good, serious complications are common:

  • Bleeding (with 55% requiring transfusion)
  • Disseminated intravascular coagulation
  • Placental abruption
  • Acute kidney injury
  • Pulmonary edema
  • Supcapsular liver hematoma or hepatic rupture
  • Retinal detachment
  • Intracerebral hemorrhage

HELLP may have neonatal outcomes depending on gestational age and birth weight at birth. Complications are generally associated with prematurity or birth complications.

Management

General Management

Due to the potential of life-threatening complications, management in tertiary centre is preferred.

Management consist of:

  • Treatment of severe hypertension
  • Hepatic imaging for bleeding and treatment with volume replacement/blood products
  • Magnesium sulfate for prevention of maternal seizures
  • Treatment of complications (eg. DIC, AKI)

Delivery

Delivery is the only effective treatment for HELLP. Following stabilization, prompt delivery is indicated for:

  • Pregnancies ≥34 weeks of gestation
  • Pregnancies <34 weeks with severe complications

For pregnancies <34 weeks without severe complications, antenatal corticosteroids are administered and delivery indicated 48 hours following.

Thrombocytopenia and coagulation abnormalities may affect use of neuraxial anesthesia but decision is made by obstetrician.

Post-Partum Management

Maternal care may include intensive care setting for complications and other supportive measures.

Laboratory monitoring may find lab results worsening in the 48 hours following birth but typically return to normal by the 4th postpartum day.

References

Tools / Guidelines

Additional Reading

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