Obstetric Topic 08. Hypertensive disorders in pregnancy. Eclampsia. HELLP-syndrome

I. Hypertensive Disorders in Pregnancy

Definition and Classification

• Hypertension in pregnancy: BP ≥140/90 mmHg.
• Severe-range BP: ≥160 systolic or ≥110 diastolic → confirm quickly and treat urgently.

1. Pre-existing / chronic hypertension: BP ≥140/90 before pregnancy or before GW20, or persists >12 weeks postpartum.
2. Gestational hypertension: new BP ≥140/90 after GW20 + no proteinuria/organ dysfunction → resolves within 12 weeks postpartum.
3. Preeclampsia: new HT after GW20 + proteinuria or maternal organ dysfunction.
4. Superimposed preeclampsia: chronic HT + new proteinuria, sudden BP worsening or organ dysfunction after GW20.
5. Eclampsia: generalized tonic-clonic seizure in preeclampsia, not explained by another cause.
6. HELLP syndrome: hemolysis + elevated liver enzymes + low platelets.

II. Preeclampsia

Definition and Risk Factors

• Preeclampsia: newly onset HT after GW20 + proteinuria >300 mg/24 h or maternal organ dysfunction; improves after delivery.
• Proteinuria: 24 h protein ≥300 mg or protein/creatinine ratio ≥0.3.
• Proteinuria is not required if severe organ dysfunction is present.
• Risk factors: primigravida, previous/family history, multiple pregnancy, advanced age, obesity.
• Maternal disease: chronic HT, diabetes, renal disease, autoimmune disease / APS, SLE.

Pathomechanism

1. Abnormal placentation: inadequate trophoblast invasion of spiral arteries → placental ischemia + HT.
2. Antiangiogenic/inflammatory factors enter maternal circulation → endothelial dysfunction.
3. Endothelial dysfunction → vasospasm + vascular permeability ↑ + coagulation activation.
4. Multiorgan involvement: brain, liver, kidney, lung, placenta, hematologic system.

Clinical Features

• May be asymptomatic → BP and urine screening are essential.
• BP >140/90 mmHg + proteinuria.
• Edema: common but not diagnostic; facial/hand edema is more concerning.
• Headache, visual disturbance, hyperreflexia.
• Epigastric/RUQ pain, nausea/vomiting.
• Oliguria/rising creatinine, dyspnea/pulmonary edema.
• Fetal clues: IUGR/FGR, oligohydramnios, abnormal NST/CTG or Doppler, placental abruption.

Diagnosis and Complications

• Diagnosis: BP + urinalysis/protein quantification.
• Labs: CBC/platelets, AST/ALT, creatinine, LDH/bilirubin if HELLP suspected.
• Fetal assessment: ultrasound growth, amniotic fluid, Doppler if FGR, NST/CTG.
• Severe features: BP ≥160/110, platelets <100 G/L, creatinine ↑, AST/ALT ↑, pulmonary edema, persistent headache/visual symptoms.
• Maternal complications: eclampsia, HELLP, acute renal failure, DIC, pulmonary edema, stroke, placental abruption.
• Fetal complications: IUGR/FGR, prematurity, hypoxia, stillbirth.

III. Management of Preeclampsia

Monitoring and Drugs

• Monitor: BP, symptoms, urine protein/output, fluid balance, platelets, creatinine, AST/ALT, fetal growth/wellbeing.
• Antihypertensives: labetalol, hydralazine, nifedipine, methyldopa.
• Methyldopa: central alpha-2 agonist.
• Seizure prevention/treatment: IV magnesium sulfate.
• MgSO4 toxicity: loss of reflexes, respiratory depression, oliguria → antidote: calcium gluconate IV.

Delivery

• Definitive treatment: delivery of placenta.
• Without severe features: delivery at ≥37 weeks.
• With severe features: delivery at ≥34 weeks after maternal stabilization.
• Earlier delivery: life-threatening maternal disease, eclampsia, HELLP deterioration, pulmonary edema, DIC, abruption or nonreassuring fetal status.
• Route: induction/vaginal delivery if feasible; cesarean for obstetric indication or fastest safe route.
• Prevention in high-risk patients: optimize chronic disease + low-dose aspirin according to protocol.

IV. Eclampsia

Definition and Clinical Features

• Eclampsia: generalized tonic-clonic seizure after GW20 or postpartum in a patient with preeclampsia.
• Pathomechanism: severe preeclampsia → cerebral vasospasm/endothelial damage → cerebral edema/ischemia → seizure.
• Warning symptoms: headache, visual disturbance, hyperreflexia, epigastric/RUQ pain, agitation.
• Complications: maternal hypoxia, aspiration, trauma, stroke, fetal bradycardia, placental abruption.

Emergency Treatment

1. Call help; left lateral position; protect from injury.
2. ABC: oxygen, suction, IV access, pulse oximetry.
3. IV MgSO4 → monitor reflexes, respiration and urine output.
4. Control severe BP: IV labetalol, IV hydralazine or oral nifedipine.
5. Fluid balance + labs + fetal surveillance after maternal stabilization.
6. Delivery after stabilization; eclampsia alone is not automatic cesarean indication.

V. HELLP Syndrome

Clinical Picture and Diagnosis

• HELLP: severe preeclampsia spectrum → Hemolysis, Elevated Liver enzymes, Low Platelets.
• May occur with absent/mild hypertension or proteinuria.
• Symptoms: rapid severe RUQ/epigastric pain, nausea, vomiting, malaise.
• Hemolysis: LDH ↑, bilirubin ↑, schistocytes/low haptoglobin if checked.
• Liver enzymes: AST/ALT ↑.
• Platelets ↓ → Mississippi classification:

• Class 3 / mild: <150 G/L.
• Class 2 / moderate: <100 G/L.
• Class 1 / severe: <50 G/L.

Complications and Treatment

• Complications: DIC, severe hemorrhage, renal failure, pulmonary edema, placental abruption.
• Liver hematoma/rupture → hemorrhagic shock; suspect with severe RUQ pain and instability.
• Stabilize mother: BP control, MgSO4, strict fluid balance, IV access, blood bank/ICU if severe.
• Blood products: RBC, platelets, FFP/cryoprecipitate according to bleeding and coagulopathy.
• Definitive treatment: prompt delivery after maternal stabilization.

VI. Postpartum and Long-Term Follow-Up

Postpartum Care

• Preeclampsia/eclampsia/HELLP can occur postpartum, usually in the first days but up to 6 weeks.
• Continue BP monitoring; antihypertensives may still be needed.
• MgSO4 is often continued 12-24 h postpartum in severe disease/eclampsia.
• Persistent HT >12 weeks postpartum → chronic hypertension evaluation.
• History of preeclampsia → higher future cardiovascular, renal and recurrent preeclampsia risk.