Safe Hypertension Medications for Pregnancy
Dihydropyridine calcium channel blockers (preferably extended-release nifedipine), labetalol, and methyldopa are the recommended first-line antihypertensive medications for treating hypertension during pregnancy. 1
First-Line Medications
Calcium Channel Blockers
- Extended-release nifedipine is a preferred first-line agent with established safety data and the advantage of once-daily dosing, improving patient adherence 1, 2
- Nifedipine has been shown to be more effective than methyldopa in achieving blood pressure control during pregnancy 3
Beta-Blockers
- Labetalol is an effective first-line agent with efficacy comparable to methyldopa 1, 4
- Labetalol should be avoided in women with reactive airway disease or asthma 2, 4
- Labetalol is the most frequently used antihypertensive medication (74.9%) for hypertensive disorders in pregnancy according to real-world data 5
Alpha-2 Agonists
- Methyldopa has the longest safety record with long-term infant outcome data 1, 6
- Methyldopa may be more poorly tolerated due to side effects including peripheral edema, dry mouth, lightheadedness, drowsiness, and effects on mood 1
- Methyldopa should be used with caution in women at risk of developing depression 2
Medications to Avoid During Pregnancy
- Renin-angiotensin system (RAS) blockers including ACE inhibitors, angiotensin receptor blockers (ARBs), and direct renin inhibitors are strictly contraindicated during pregnancy due to severe fetotoxicity 1, 2
- Diuretics are generally not recommended during pregnancy due to the risk of reducing uteroplacental perfusion 1, 2
- Atenolol should be avoided due to the risk of fetal growth restriction 1, 7
Blood Pressure Targets and Treatment Thresholds
- Treatment should be initiated when blood pressure is ≥140/90 mmHg in pregnant women with chronic or gestational hypertension 1
- Target blood pressure should be below 140/90 mmHg but not below 80 mmHg for diastolic BP 1
- Severe hypertension (>160/110 mmHg) requires urgent treatment in a monitored setting 1, 7
Management of Severe Hypertension
- For severe hypertension (>160/110 mmHg), immediate treatment options include:
Special Considerations
Pre-conception Planning
- Women planning pregnancy should transition to pregnancy-safe antihypertensive medications before conception 2
- ACE inhibitors, ARBs, and direct renin inhibitors must be discontinued prior to conception or as soon as pregnancy is confirmed 1, 2
Postpartum Management
- First-line agents for postpartum hypertension regardless of breastfeeding status include nifedipine, amlodipine, enalapril, and labetalol 1
- Recent data suggest that labetalol may be less effective in the postpartum period compared to calcium channel blockers 1
Common Pitfalls to Avoid
- Failing to transition from contraindicated medications (ACE inhibitors/ARBs) before conception or early in pregnancy 1, 2
- Using atenolol during pregnancy, which is associated with fetal growth restriction 1, 8
- Inadequate monitoring of blood pressure during pregnancy, which should include testing for orthostatic hypotension 1
- Excessive lowering of diastolic blood pressure below 80 mmHg, which may impair uteroplacental perfusion 1
Monitoring Recommendations
- Blood pressure target during pregnancy should be 110-135/85 mmHg to reduce the risk of accelerated maternal hypertension while minimizing impairment of fetal growth 2
- Women with hypertension in pregnancy should be assessed in hospital when first diagnosed; thereafter, some may be managed as outpatients once their condition is stable 1