Management of Hypertension in Pregnancy
For pregnant women with hypertension, initiate pharmacological treatment with extended-release nifedipine, labetalol, or methyldopa when blood pressure reaches ≥140/90 mmHg, targeting 110-135/85 mmHg, and immediately discontinue all ACE inhibitors, ARBs, and direct renin inhibitors due to severe fetal toxicity. 1, 2, 3
Immediate Medication Changes
ACE inhibitors, ARBs, direct renin inhibitors, mineralocorticoid receptor antagonists, and neprilysin inhibitors are absolutely contraindicated throughout pregnancy and must be stopped immediately due to associations with fetal teratogenicity, oligohydramnios, and severe fetotoxicity. 1, 2, 3, 4
Women of childbearing potential taking these medications should transition to pregnancy-safe alternatives before conception attempts begin. 2
First-Line Pharmacological Options
The three evidence-based first-line medications are:
Extended-release nifedipine (dihydropyridine calcium channel blocker): Preferred first-line agent with strongest safety data and once-daily dosing advantage 1, 2, 3. Only extended-release formulations should be used for chronic management; short-acting nifedipine is reserved for hypertensive emergencies. 2
Labetalol (alpha/beta-blocker): Excellent alternative, particularly for women without reactive airway disease 1, 2, 5. Efficacy comparable to methyldopa. 6
Methyldopa: Has the longest safety record with adequate infant follow-up data (7.5 years) 3, 7, though should be used cautiously in women at risk for depression. 2
Blood Pressure Targets and Treatment Thresholds
Initiate treatment at BP ≥140/90 mmHg for all pregnant women with confirmed hypertension. 1, 3, 6
Target BP should be 110-135/85 mmHg to balance maternal cardiovascular protection with adequate uteroplacental perfusion. 1, 2 The diastolic BP should not fall below 80 mmHg to ensure adequate uteroplacental perfusion. 3, 6
For severe hypertension (SBP ≥170 mmHg or DBP ≥110 mmHg), this constitutes an emergency requiring hospitalization and immediate pharmacological treatment with IV labetalol, oral methyldopa, or nifedipine. 3, 6
Diuretic Considerations
Diuretics are not recommended for blood pressure management in pregnancy due to risk of reducing uteroplacental perfusion and plasma volume expansion. 1, 2 However, they may be used during late-stage pregnancy if needed for volume management. 1
If a woman is already established on diuretics before pregnancy, they are probably safe to continue, but this should be carefully evaluated. 2
Non-Pharmacological Management
Low to moderate-intensity exercise is recommended for all pregnant women without contraindications to reduce risk of gestational hypertension and pre-eclampsia. 2, 6
Normal diet without salt restriction is advised, particularly close to delivery, as salt restriction may induce low intravascular volume. 3
Low-dose aspirin (75-150 mg daily) should be started at bedtime before 16 weeks gestation in women with history of early-onset (<28 weeks) pre-eclampsia. 2, 3, 6
Calcium supplementation (≥1 g daily) may be beneficial, particularly in high-risk women. 6
Monitoring Strategy
Regular BP monitoring throughout pregnancy is essential. 3, 6
Monitor for signs of worsening hypertension or development of pre-eclampsia (headache, visual disturbances, epigastric pain). 3
Evaluate for proteinuria to detect pre-eclampsia (≥0.3 g/day in 24-hour urine collection or ≥30 mg/mmol urinary creatinine in spot random urine). 3
Baseline laboratory evaluation should include complete blood count, liver enzymes, serum creatinine, electrolytes, uric acid, and urinalysis with protein-to-creatinine ratio. 2
Postpartum Management
Continue antihypertensive medications postpartum with gradual tapering rather than abrupt cessation. 3 Safe medications for breastfeeding mothers include labetalol, nifedipine, methyldopa, and enalapril. 3
Women with gestational hypertension, preeclampsia, and superimposed preeclampsia should have BP observed for 72 hours in the hospital and 7-10 days postpartum. 1
All women should be reviewed at 3 months postpartum to ensure BP, urinalysis, and laboratory abnormalities have normalized. 3
Long-Term Cardiovascular Risk
Women with hypertensive disorders of pregnancy have significantly elevated lifetime cardiovascular risk and require annual cardiovascular risk assessment lifelong. 1, 2, 3 These women should aim to achieve pre-pregnancy weight by 12 months and adopt a healthy lifestyle including regular exercise, healthy diet, and maintaining ideal body weight. 3
Critical Pitfalls to Avoid
Failing to discontinue ACE inhibitors/ARBs before conception is the most critical error, as 50% of pregnancies are unplanned and early exposure causes fetal harm. 2
Using short-acting nifedipine for maintenance therapy—only extended-release formulations should be used chronically. 2
Avoiding calcium channel blockers due to outdated concerns—oral extended-release formulations are safe and effective; only rapid IV/sublingual administration causes problems. 2
Avoiding atenolol specifically, as it is associated with intrauterine growth restriction. 2