A 28-year-old primigravida at 34 weeks of gestation presents to the antenatal clinic with a complaint of headache and blurred vision for the past 6 hours. On examination, blood pressure is 168/110 mmHg (baseline 110/70 mmHg at 20 weeks). Urine dipstick shows 2+ proteinuria. Deep tendon reflexes are brisk with ankle clonus present. Fetal heart rate is 142 bpm with normal variability. Laboratory investigations show platelet count 95,000/μL, serum creatinine 1.4 mg/dL, and AST 68 U/L. What is the most appropriate immediate management?

Explanation

## Clinical Diagnosis: Severe Preeclampsia with Imminent Eclampsia ### Recognition of Severity Criteria **Key Point:** This patient meets criteria for severe preeclampsia with features of impending eclampsia: - Systolic BP ≥160 mmHg or diastolic BP ≥110 mmHg - Neurological symptoms (headache, blurred vision) - Hyperreflexia with ankle clonus (sign of cerebral irritability) - Thrombocytopenia (platelets <100,000/μL) - Elevated liver enzymes (AST >40 U/L) - Elevated creatinine (>1.2 mg/dL) - Significant proteinuria (≥2+) ### Management Algorithm for Severe Preeclampsia at 34 Weeks ```mermaid flowchart TD A[Severe Preeclampsia at 34 weeks]:::outcome --> B{Eclampsia/Imminent eclampsia signs?}:::decision B -->|Yes| C[Magnesium sulphate for seizure prophylaxis]:::action B -->|No| D[Antihypertensive monotherapy] C --> E[IV MgSO4: 4g bolus + 1g/hr infusion]:::action E --> F[Administer corticosteroids for fetal lung maturity]:::action F --> G[Plan delivery within 24 hours]:::action G --> H{Maternal/fetal stability?}:::decision H -->|Stable| I[Vaginal delivery trial acceptable]:::action H -->|Unstable| J[Cesarean section]:::urgent ``` ### Magnesium Sulphate Regimen | Parameter | Detail | |-----------|--------| | **Loading dose** | 4 g IV over 20–30 minutes | | **Maintenance** | 1 g/hour IV infusion | | **Duration** | Continue for 12–24 hours postpartum | | **Mechanism** | NMDA antagonist; stabilizes cerebral vasculature; prevents eclamptic seizures | | **Efficacy** | Reduces seizure risk by ~58% in severe preeclampsia | **Clinical Pearl:** Magnesium sulphate is the gold standard for seizure prophylaxis in severe preeclampsia and eclampsia worldwide. It is superior to phenytoin and diazepam in reducing maternal morbidity and mortality. ### Corticosteroid Administration **High-Yield:** At 34 weeks gestation, administer betamethasone 12 mg IM (two doses 24 hours apart) or dexamethasone 6 mg IM (four doses 12 hours apart) to accelerate fetal lung maturity and reduce neonatal respiratory distress, intraventricular hemorrhage, and necrotizing enterocolitis. ### Timing of Delivery **Key Point:** In severe preeclampsia at ≥34 weeks, delivery should be planned within 24 hours after maternal stabilization and corticosteroid administration, unless there is maternal or fetal compromise requiring immediate delivery. ### Antihypertensive Targets - **Acute severe hypertension (SBP ≥160 or DBP ≥110):** Reduce by 15–25% in first hour using IV labetalol or oral immediate-release nifedipine - **Maintenance:** Target BP 140–150/90–100 mmHg to avoid placental hypoperfusion [cite:Williams Obstetrics 26e Ch 34]