Antihypertensive Medications Safe for Women Planning Pregnancy
Women planning pregnancy should be transitioned to methyldopa, extended-release nifedipine, or labetalol before conception, as these are the only antihypertensive agents with established safety profiles during pregnancy. 1
Medications to START Before Conception
First-Line Options (Choose One)
Extended-release nifedipine is increasingly preferred as the first-line agent due to:
- Strong safety record throughout pregnancy 2, 3
- Once-daily dosing that improves adherence 2
- Superior efficacy in preventing progression to severe hypertension 4
- Lower risk of persistent hypertension compared to other agents 4
Labetalol is an excellent alternative when:
- Nifedipine is not tolerated 2
- Patient has no history of reactive airway disease (absolute contraindication) 2
- Dosing: Start 100 mg twice daily, titrate up to maximum 2400 mg/day 3, 5
Methyldopa has the longest safety record with long-term infant follow-up data but:
- Should be used with caution in women at risk for depression 2, 6
- Has more side effects than labetalol or nifedipine 6, 7
- Must be switched to alternative agent postpartum due to depression risk 6, 3
Medications to STOP Before Conception
Absolutely contraindicated - discontinue immediately when planning pregnancy:
- ACE inhibitors (e.g., lisinopril, enalapril) - cause fetal renal dysgenesis, oligohydramnios, and death 1, 2
- Angiotensin receptor blockers (ARBs) (e.g., losartan, valsartan) - same fetal toxicity as ACE inhibitors 1, 2
- Direct renin inhibitors (e.g., aliskiren) - fetotoxic 1, 2
- Mineralocorticoid receptor antagonists (e.g., spironolactone) - associated with fetal teratogenicity 2
These agents must be discontinued prior to attempts at conception or as soon as pregnancy is confirmed. 1
Medications to Use With Caution
Atenolol should be avoided, especially in early pregnancy, due to concerns about intrauterine growth retardation 1, 6
Diuretics should generally be avoided during pregnancy due to:
- Risk of reducing uteroplacental perfusion 2, 6
- Increased risk of hypokalemia and hyponatremia in women 1
- May reduce milk production postpartum 3
Preconception Transition Algorithm
Identify current antihypertensive regimen - If on ACE inhibitor, ARB, or direct renin inhibitor, immediate transition is required 1
Select pregnancy-safe alternative:
Achieve blood pressure control before conception - Target <140/90 mmHg 6
Screen for secondary hypertension - Consider pheochromocytoma screening in women with severe hypertension due to high morbidity/mortality if undiagnosed during pregnancy 1
Critical Pitfalls to Avoid
Do not use short-acting nifedipine for maintenance therapy - reserve only for acute severe hypertension, as it can cause uncontrolled hypotension, especially when combined with magnesium sulfate 3
Do not continue methyldopa postpartum - switch to alternative agent due to depression risk 6, 3
Do not assume blood pressure will remain controlled in early pregnancy - BP typically falls in first trimester, requiring medication adjustment 1
Do not use sublingual or IV nifedipine - risk of precipitous hypotension and myocardial infarction 3
Monitoring During Preconception Period
- Blood pressure should be monitored regularly to ensure control on pregnancy-safe medications 2
- Target blood pressure: <140/90 mmHg before conception 6
- Once pregnant, target changes to 110-135/85 mmHg to balance maternal protection with fetal growth 2, 6
Special Considerations
Women with moderate-to-severe renal insufficiency (serum creatinine >1.4 mg/dL) should be counseled that pregnancy may accelerate hypertension and underlying disease, with markedly reduced fetal survival 1
Long-term cardiovascular risk - Women with hypertension during pregnancy have increased risk of developing cardiovascular disease later in life, requiring lifelong monitoring 2, 6