HELLP Syndrome
HELLP syndrome is one of the most severe hypertensive disorders of pregnancy and is considered a life-threatening obstetric emergency.
HELLP = Hemolysis + Elevated Liver Enzymes + Low Platelet Count
It is now regarded as a severe variant of preeclampsia
HELLP syndrome is a pregnancy-specific thrombotic microangiopathy characterized by:
H – Hemolysis
Evidence of microangiopathic hemolytic anemia:
- Schistocytes on peripheral smear
- Elevated LDH
- Low haptoglobin
- Increased indirect bilirubin
EL – Elevated Liver Enzymes
- AST elevation/ALT elevation
- Hepatic ischemia and necrosis
LP – Low Platelets
- Platelet consumption due to endothelial injury
- Usually <100,000/mm³
Timing:
|
Timing |
Frequency |
|
Antepartum |
70% |
|
Postpartum |
30% |
Most common:27–37 weeks gestation
Postpartum HELLP:
- Usually within first 48 hours
- Can occur up to 7 days postpartum
Pathophysiology
Step 1: Abnormal placentation
Failure of trophoblast invasion causes:
- Narrow spiral arteries
- High resistance uteroplacental circulation
- Placental ischemia
↓
Step 2: Placental release of antiangiogenic factors
Major mediators:sFlt-1—-Soluble endoglin
Result:Systemic endothelial injury
↓
Step 3: Endothelial dysfunction
Causes:
- Vasoconstriction
- Platelet activation
- Coagulation activation
↓
Step 4: Microvascular thrombosis
Especially in:Liver/Kidney/Brain/Placenta
↓
Step 5: Microangiopathic hemolysis
RBCs pass through narrowed vessels.
Result:Schistocyte formation—Hemolysis
↓
Step 6: Platelet consumption
Platelets aggregate around damaged endothelium.
↓
Thrombocytopenia
↓
Step 7: Hepatic injury
Sinusoidal obstruction causes:
- Periportal necrosis
- Hepatic hemorrhage
- Subcapsular hematoma
Risk Factors
Maternal factors:
- Previous HELLP
- Previous preeclampsia
- Chronic hypertension
- Diabetes
- CKD
- APS
- Obesity
- Multiparity
- Advanced maternal age
Clinical Features
|
Category |
Clinical Features |
|
Right upper quadrant (RUQ) pain |
Most common symptom; present in >80% of patients |
|
Cause of RUQ pain |
Liver swelling and stretching of Glisson’s capsule |
|
Epigastric pain |
Important warning sign; may precede severe complications |
|
Nausea |
Common presenting symptom |
|
Vomiting |
Common presenting symptom |
|
Malaise |
Frequently reported |
|
Classic description |
“Flu-like illness in late pregnancy” |
|
Neurologic Symptoms |
|
|
Headache |
Common, often severe and persistent |
|
Visual disturbances |
Blurred vision, scotomata, flashing lights |
|
Confusion |
May indicate cerebral involvement |
|
Seizures |
Suggest progression to eclampsia |
|
Signs |
|
|
Hypertension |
Present in most patients |
|
Important point |
15–20% may not have severe hypertension |
|
Proteinuria |
Common but not mandatory for diagnosis |
|
Edema |
May occur but is nonspecific and not required for diagnosis |
Diagnostic Criteria-Tennessee Classification
Diagnosis requires all three components (H + EL + LP):
|
Component |
Diagnostic Criteria |
|
H – Hemolysis |
Presence of one or more of the following: |
|
|
Schistocytes on peripheral blood smear |
|
|
LDH >600 IU/L |
|
|
Total bilirubin >1.2 mg/dL |
|
EL – Elevated Liver Enzymes |
AST ≥70 IU/L |
|
LP – Low Platelets |
Platelet count <100,000/mm³ |
Important Point:
The Tennessee system defines complete HELLP syndrome only when all three criteria (Hemolysis + Elevated Liver Enzymes + Low Platelets) are present simultaneously. Patients fulfilling only one or two components are often described as having partial or incomplete HELLP syndrome.
Mississippi Classification
Based on platelet count.
|
Class |
Platelet Count |
|
Class I |
<50,000 |
|
Class II |
50,000–100,000 |
|
Class III |
100,000–150,000 |
Class I has highest maternal mortality.
Investigation
|
Investigation |
Findings |
|
CBC |
Thrombocytopenia (hallmark finding) |
|
|
Falling hemoglobin (Hb) due to hemolysis |
|
Peripheral Smear |
Schistocytes |
|
|
Burr cells |
|
|
Helmet cells |
|
Hemolysis Markers |
↑ LDH (often >600 IU/L) |
|
|
Severe disease: LDH >1000 IU/L |
|
|
↑ Indirect bilirubin |
|
|
↓ Haptoglobin |
|
|
↑ Reticulocyte count |
|
Liver Function Tests |
↑ AST/↑ ALT Usually 100–700 IU/L Can exceed 2000 IU/L in severe cases |
|
Coagulation Profile |
Usually normal initially |
|
|
May show prolonged PT when DIC develops |
|
|
May show prolonged aPTT when DIC develops |
|
|
Low fibrinogen when DIC develops |
|
Renal Findings |
Proteinuria |
|
|
Increased serum creatinine |
|
|
Acute kidney injury (AKI) |
Imaging
|
Aspect |
Details |
|
Routine role |
Not routinely required |
|
Indications for imaging |
Severe right upper quadrant (RUQ) pain |
|
|
Shock |
|
|
Sudden fall in hemoglobin |
|
Purpose |
To rule out hepatic hematoma |
|
|
To rule out hepatic rupture |
|
Initial imaging test |
Ultrasound |
|
Most sensitive imaging modality |
CT abdomen |
Differential Diagnosis
1. Severe Preeclampsia
HELLP has:
- More thrombocytopenia
- More hemolysis
- More liver injury
2. Acute Fatty Liver of Pregnancy (AFLP)
|
Feature |
HELLP |
AFLP |
|
Hemolysis |
Common |
Rare |
|
Platelets |
Low |
Mild ↓ |
|
Hypoglycemia |
Rare |
Common |
|
Encephalopathy |
Rare |
Common |
|
Hyperbilirubinemia |
Mild |
Marked |
3. TTP
Features favoring TTP:
- Severe thrombocytopenia
- Severe neurologic dysfunction
- Normal pregnancy BP
- Low ADAMTS13
4. HUS
Features favoring HUS:
- Severe AKI
- Less liver involvement
5. Viral Hepatitis
AST/ALT often >1000–5000.
Platelets usually preserved.
Maternal Complications of HELLP Syndrome
|
Complication |
Details |
|
Disseminated Intravascular Coagulation (DIC) |
Occurs in 15–30% of cases |
|
|
Most common severe maternal complication |
|
Placental Abruption |
Occurs in 5–20% of cases |
|
|
Major cause of fetal death |
|
Acute Kidney Injury (AKI) |
Occurs in 7–15% of cases |
|
|
Mechanisms: Endothelial injury, DIC, Acute Tubular Necrosis (ATN) |
|
Pulmonary Edema |
Due to capillary leak syndrome |
|
|
May also result from fluid overload |
|
Acute Respiratory Distress Syndrome (ARDS) |
Results from severe inflammatory lung injury |
|
Eclampsia |
May occur before HELLP syndrome is diagnosed |
|
Hepatic Hematoma |
Rare but potentially catastrophic complication |
|
Hepatic Rupture |
Maternal mortality: 30–80% |
|
|
Suspect in patients with sudden severe RUQ pain |
|
|
Associated with shock |
|
|
Associated with sudden hemoglobin drop |
|
Stroke (Intracranial Hemorrhage or Ischemic Stroke) |
Usually secondary to severe hypertension |
|
Maternal Death |
Usually due to DIC, hepatic rupture, intracranial hemorrhage, or multiorgan failure |
Fetal Complications of HELLP Syndrome
|
Complication |
Details |
|
Prematurity (Preterm Birth) |
Most common fetal complication |
|
|
Often results from indicated early delivery for maternal stabilization |
|
Intrauterine Growth Restriction (IUGR) |
Due to chronic placental insufficiency and uteroplacental hypoperfusion |
|
Fetal Distress |
Secondary to impaired placental blood flow and fetal hypoxia |
|
Placental Abruption |
Premature separation of placenta; major contributor to fetal morbidity and mortality |
|
Stillbirth (Intrauterine Fetal Death) |
May occur due to severe placental insufficiency, abruption, or fetal hypoxia |
|
Neonatal Mortality |
Primarily related to complications of prematurity rather than HELLP syndrome itself |
|
Low Birth Weight |
Common due to prematurity and fetal growth restriction |
|
NICU Admission |
Frequently required because of prematurity, respiratory distress, and low birth weight |
|
Neonatal Respiratory Distress Syndrome (RDS) |
Increased risk in preterm infants delivered because of HELLP syndrome |
|
Perinatal Mortality |
Increased due to prematurity, placental abruption, fetal distress, and stillbirth |
ICU Management
Blood Pressure Control
Treat:SBP ≥160 or DBP ≥110
Drugs: IV Labetalol/ IV Hydralazine/Oral Nifedipine
Target:140–150/90–100 mmHg
Avoid excessive BP reduction.
Magnesium Sulfate
Given to ALL HELLP patients with severe features.
Purpose:Seizure prophylaxis
Loading:4–6 g IV Then: 1–2 g/hr infusion
Monitor:
- Reflexes
- Respiratory rate
- Urine output
Antidote:Calcium gluconate 10 mL of 10% solution IV
Fluid Management
Patients have:
- Intravascular depletion
- Extravascular overload
Avoid aggressive fluids.
Goal-directed therapy preferred.
Platelet Transfusion
- No bleeding Usually not required if:Platelets >20,000
- Vaginal Delivery—20,000–50,000
- Cesarean Section—: 50,000
- Neuraxial AnesthesiaGenerally:70,000–80,000 with stable counts and normal coagulation.
Corticosteroids
Routine maternal steroid therapy solely for HELLP is not universally recommended.
Fetal Indication
If <34 weeks:Betamethasone for fetal lung maturation.
Definitive Treatment
DELIVERY The only cure.
Removal of placenta removes the disease driver.
Timing of Delivery
- ≥34 Weeks-Immediate delivery recommended.
- <34 Weeks-If mother and fetus stable:
Short course (24–48 h) for:Steroids —Transfer to tertiary center Then delivery.
Immediate Delivery Regardless of Gestational Age
Required if:
- DIC
- Eclampsia
- Pulmonary edema
- Liver hematoma
- Hepatic rupture
- Uncontrolled hypertension
- Nonreassuring fetal status
- Placental abruption
- Multiorgan failure
Mode of Delivery-Vaginal Delivery Preferred when feasible.
Cesarean Section
Indications:
- Obstetric indication
- Fetal distress
- Unfavorable cervix with urgent need
Postpartum HELLP
HELLP may worsen after delivery.
Platelets often continue falling for:24–48 hours postpartum.
Therefore:ICU monitoring should continue.
Prognosis
Laboratory recovery:
- Platelets improve in 3–4 days
- LFTs normalize within days to weeks
Clinical Pearls
- RUQ pain in a preeclamptic patient = HELLP until proven otherwise.
- LDH elevation is the most sensitive marker of hemolysis.
- Most dangerous maternal complications: DIC, hepatic rupture, intracranial hemorrhage.
- Platelets may continue to fall for 24–48 h after delivery.
- Severe RUQ pain + shock + falling Hb = suspect hepatic hematoma/rupture.