A 28-year-old primigravida at 16 weeks of gestation presents with severe hypertension (BP 160/110 mmHg) and proteinuria. She was on lisinopril 10 mg daily for chronic hypertension before pregnancy. What is the most appropriate immediate next step in management?

Explanation

## Management of Hypertension in Pregnancy ### ACE Inhibitor Teratogenicity **Key Point:** ACE inhibitors and ARBs are contraindicated throughout pregnancy, especially in the second and third trimesters. They are associated with renal dysgenesis, oligohydramnios, intrauterine growth restriction, and fetal/neonatal renal failure and death. **High-Yield:** Lisinopril must be discontinued immediately upon confirmation of pregnancy or when pregnancy is planned. There is no safe trimester for ACE inhibitor use in pregnancy. ### Safe Antihypertensive Agents in Pregnancy | Drug Class | Safety Profile | Notes | |---|---|---| | Methyldopa | Category A (safest) | First-line; slow onset; used for chronic hypertension | | Nifedipine (extended-release) | Category C (safe in pregnancy) | Preferred calcium channel blocker; no fetal hypoxia | | Labetalol | Category C (safe) | Combined α/β-blocker; good for acute and chronic use | | Hydralazine | Category C (safe) | Reserved for acute severe hypertension; not monotherapy | | Atenolol | **Contraindicated** | Associated with IUGR and preterm delivery; avoid | | ACE inhibitors / ARBs | **Contraindicated** | Teratogenic; renal dysgenesis, oligohydramnios, fetal death | | Diuretics | Relative caution | May reduce placental perfusion; use only if essential | | Atenolol | **Contraindicated** | Associated with IUGR and preterm delivery | ### Recommended Approach 1. **Discontinue lisinopril immediately** — it is teratogenic and must not be continued. 2. **Initiate methyldopa** (500 mg BD–TDS) — first-line agent for chronic hypertension in pregnancy; long safety record (Category A). 3. **Add nifedipine extended-release** (20–30 mg daily) — safe calcium channel blocker for additional BP control. 4. **Monitor for preeclampsia** — proteinuria + hypertension at 16 weeks raises concern for early-onset preeclampsia. **Clinical Pearl:** Methyldopa has the longest safety record in pregnancy (used since the 1960s) and is preferred for chronic hypertension. Nifedipine extended-release is the preferred second-line agent; immediate-release nifedipine is reserved for acute severe hypertension. **Mnemonic: SAFE drugs in pregnancy — Methyldopa, Amlodipine/Nifedipine, Labetalol, Hydralazine (acute only), Atenolol (avoid)** ### Why Discontinuation is Urgent ACE inhibitor exposure in the second trimester is associated with: - Renal dysgenesis and agenesis - Oligohydramnios - Intrauterine growth restriction - Neonatal hypotension, renal failure, and death The risk is highest in the second and third trimesters but exposure in any trimester warrants careful counselling and fetal assessment. [cite:KD Tripathi 8e Ch 12] [cite:Harrison 21e Ch 297]