What are the diagnostic criteria and management options for a pregnant woman, likely in her second or third trimester with a history of preeclampsia or hypertension, suspected of having Hemolysis, Elevated Liver enzymes, and Low Platelet count (HELLP) syndrome?

HELLP Syndrome Diagnostic Criteria

HELLP syndrome is diagnosed by the presence of hemolysis (with schistocytes on peripheral smear), elevated liver enzymes (AST >70 U/L), and thrombocytopenia (platelets <100,000/mm³), and should be recognized as a manifestation of severe preeclampsia requiring urgent delivery once maternal stabilization is achieved. 1, 2

Diagnostic Criteria

The diagnosis requires all three components of the triad:

Hemolysis

• Peripheral blood smear must show schistocytes and fragmented red blood cells 3
• Elevated LDH >295 U/L (reflects both hemolysis and hepatic dysfunction) 3
• Elevated indirect bilirubin (may reach 18 µmol/L or higher) 3
• Elevated fibrin degradation products (>80 µg/L, normal <10 µg/L) indicating microangiopathic process 3

Elevated Liver Enzymes

• AST >70 U/L (Tennessee Classification) or >200 U/L (more severe cases) 2, 3
• ALT >159 U/L 3
• LDH >600 U/L 4

Low Platelet Count

• Platelets <100,000/mm³ (Tennessee Classification threshold) 2, 3, 4
• The Mississippi Triple-class System further stratifies by nadir platelet counts for severity assessment 4

Classification Systems

Two main systems exist, though the Tennessee Classification is more widely referenced:

• Tennessee Classification: Requires hemolysis (LDH >600 U/L), AST ≥70 U/L, and platelets <100 × 10⁹/L 4
• Mississippi Triple-class System: Further classifies by platelet nadir for severity stratification 4

The syndrome may be complete (all three components) or incomplete 4

Critical Clinical Context

HELLP syndrome is not a separate disorder but represents the severe end of the preeclampsia spectrum 1

Timing and Presentation

• 70% of cases develop before delivery, predominantly between 27-37 weeks gestation 4
• 30% occur or worsen within 48 hours postpartum, necessitating vigilant monitoring 5
• May present without classic preeclampsia features (hypertension, proteinuria), leading to misdiagnosis 6, 7

Associated Clinical Features

• Right upper quadrant or epigastric pain (present in 65% of symptomatic patients) 3
• Nausea and vomiting 3
• Hypertension (may progress from 130/80 to ≥160/95 mmHg) 3
• Proteinuria is present in only ~75% of cases 1

Essential Laboratory Workup

When evaluating suspected HELLP syndrome, obtain:

• Complete blood count with peripheral smear examination for schistocytes 2, 3
• Comprehensive metabolic panel including AST, ALT, LDH, total and indirect bilirubin 2, 5
• Coagulation studies (PT, aPTT, fibrinogen, fibrin degradation products) 3
• Renal function tests 1

Note: Coagulation studies (PT, aPTT, fibrinogen) are typically normal in HELLP syndrome, distinguishing it from DIC 3

Critical Pitfalls to Avoid

Misdiagnosis Risk

• Patients are frequently misdiagnosed with nonobstetric conditions (gastrointestinal or hematologic disease) when classic preeclampsia features are absent 6, 7
• The absence of severe hypertension or proteinuria does not exclude HELLP syndrome 1, 6

Life-Threatening Complications Requiring Immediate Imaging

If severe thrombocytopenia (<50,000/mm³) occurs with persistent right upper quadrant pain, immediately perform abdominal ultrasound or CT to rule out subcapsular hematoma or hepatic rupture 2, 5, 3

• Persistent epigastric pain with worsening liver enzymes mandates urgent imaging 5, 3
• Hepatic complications carry maternal mortality rates of 2-24% 3

Management Priorities

Immediate Stabilization

Women with HELLP syndrome should be delivered promptly once maternal coagulopathy and severe hypertension have been corrected 1

Blood Pressure Management

• Non-severe hypertension (140-159/90-109 mmHg): Initiate oral labetalol, nifedipine, or methyldopa 1
• Severe hypertension (≥160/110 mmHg): Treat urgently with oral agents; IV labetalol or hydralazine may be required 1
• Target: Keep BP <155/105 mmHg 4

Seizure Prophylaxis

Magnesium sulfate must be given to women with HELLP syndrome and co-existing severe hypertension to prevent eclamptic seizures 1

Transfusion Thresholds

• Platelet transfusion should be considered when count <100,000/mm³ (associated with increased coagulopathy risk) 1
• Transfuse platelets if <50,000/mm³ before cesarean section 2, 3
• Administer fresh frozen plasma to correct coagulopathy before surgical intervention 2

Corticosteroid Use

• Do NOT give corticosteroids to improve maternal outcomes in HELLP syndrome 1
• DO give high-dose dexamethasone or betamethasone for fetal lung maturity if delivery required before 35 weeks 1
• Single course only (2 doses betamethasone 12 mg 24 hours apart, or dexamethasone 6 mg 12 hours apart) 4
• Avoid repeated doses due to long-term fetal brain effects 4

Anesthesia Considerations

Regional anesthesia (epidural/spinal) is contraindicated with elevated INR or platelets <100,000/mm³ due to epidural hematoma risk 2

Postpartum Monitoring

Critical Surveillance Period

• Monitor in high-dependency or intensive care setting for at least 24-48 hours post-delivery 5
• Continue laboratory monitoring every 6-12 hours for 24-48 hours postpartum 5, 3
• Monitor central venous pressure, urinary output, BP, ECG, and oxygen saturation 5

Expected Recovery Timeline

• Platelet counts typically recover first, often reaching >100,000/mm³ by postoperative day 2 5
• Most laboratory parameters improve within 24-48 hours after delivery 5
• Liver enzymes typically normalize within one week, though may take up to 10 days 5

Warning Signs of Complications

• Progressive thrombocytopenia beyond 5 days postpartum suggests ongoing disease or hepatic complications 5
• Persistent symptoms beyond 5 days warrant further investigation 5

Risk Stratification and Prevention

Future Pregnancy Counseling

Women with prior HELLP syndrome should undergo first-trimester screening to assess early-onset preeclampsia risk 1

Prophylaxis for High-Risk Women

Following first-trimester screening, high-risk women should receive aspirin 150 mg nightly starting before 16 weeks' gestation until 36 weeks, delivery, or HELLP diagnosis 1

• In women with low calcium intake (<800 mg/day), consider calcium supplementation (1.5-2 g elemental calcium/day) 1