It is not intended for lay persons. Prescribers must review full product labeling and current guidelines prior to use.
Overview
This page summarizes commonly used antihypertensive medications in pregnancy for chronic hypertension, gestational hypertension, and preeclampsia. Labetalol, nifedipine, methyldopa, and hydralazine have the most pregnancy safety data and are recommended first-line. ACE inhibitors, ARBs, and direct renin inhibitors are contraindicated in pregnancy because of fetal toxicity.
Chronic / Non-severe Hypertension — First-Line Agents
For most pregnant patients requiring ongoing pharmacologic therapy, first-line oral options include labetalol, nifedipine extended-release, and methyldopa; low-dose thiazide diuretics can be continued in selected women already taking them before pregnancy.
| Drug | Usual Oral Dose Range | Comments |
|---|---|---|
| Labetalol |
Start 100–200 mg orally twice daily; usual total 200–2,400 mg/day in 2–3 divided doses. |
Mixed α/β-blocker; avoid in asthma, heart block, bradycardia, or decompensated heart failure. |
| Nifedipine ER |
Start 30–60 mg once daily; titrate up to 120 mg/day. |
Dihydropyridine calcium-channel blocker; avoid in marked tachycardia. |
| Methyldopa |
Start 250 mg orally twice or three times daily; usual total 500–3,000 mg/day in divided doses. |
Long safety experience; slower onset; can cause sedation, depression, elevated liver enzymes. |
| Hydrochlorothiazide | 12.5–25 mg once daily. | Can be continued if effective before pregnancy; avoid volume depletion; monitor electrolytes. |
• Traditional ACOG thresholds treated chronic hypertension when BP ≥ 160/110 mm Hg.
• CHAP trial supports treating mild chronic hypertension to maintain BP < 140/90 mm Hg without increasing SGA risk.
Acute-Onset Severe Hypertension
Acute-onset severe hypertension (systolic ≥ 160 mm Hg and/or diastolic ≥ 110 mm Hg persisting ≥ 15 minutes) during pregnancy or postpartum requires urgent treatment to reduce the risk of stroke and other serious maternal complications.
First-line agents: IV labetalol, IV hydralazine, or immediate-release oral nifedipine.
1. Labetalol (IV)
- Initial dose: 20 mg IV over 2 minutes
- If BP remains ≥ 160/110 mm Hg after 10 minutes → 40 mg IV
- Then 80 mg IV every 10 minutes as needed (maximum cumulative 220 mg)
2. Hydralazine (IV)
- Initial dose: 5–10 mg IV over 2 minutes
- Repeat 5–10 mg IV every 20 minutes as needed (maximum 30 mg)
3. Nifedipine (Immediate-Release, Oral)
- Initial dose: 10–20 mg orally
- Repeat 10–20 mg in 20 minutes if still ≥ 160/110 mm Hg
- Then 10–20 mg orally every 2–6 hours as needed (maximum 180 mg/day)
• Check BP frequently (e.g., every 10–15 minutes) until controlled, then at least hourly.
• Monitor fetal status once maternal condition is stabilized.
• Evaluate for superimposed preeclampsia and other end-organ complications.
Agents to Avoid in Pregnancy
Certain classes of antihypertensives are associated with fetal renal dysgenesis, oligohydramnios, skull ossification defects, and neonatal renal failure and should not be used in pregnant patients except in rare, life-threatening circumstances where no alternatives are possible.
- ACE inhibitors (e.g., enalapril, lisinopril, captopril)
- Angiotensin receptor blockers (ARBs) (e.g., losartan, valsartan)
- Direct renin inhibitors (e.g., aliskiren)
- Mineralocorticoid receptor antagonists (e.g., spironolactone, eplerenone) — antiandrogenic and limited pregnancy data
If a patient becomes pregnant while taking an ACE inhibitor or ARB, these medications should be discontinued and changed to a safer alternative as soon as pregnancy is recognized.
Postpartum Considerations
Postpartum BP may peak 3–6 days after delivery. Labetalol and nifedipine are generally compatible with breastfeeding. Some clinicians consider resuming pre-pregnancy agents (e.g., ACE inhibitors such as enalapril) in the postpartum period when not breastfeeding or when compatible with lactation.
UPDATED 12/4/2025
References (click to expand)
References
1. American College of Obstetricians and Gynecologists. Practice Bulletin No. 203: Chronic Hypertension in Pregnancy.
Obstet Gynecol. 2019;133(1):e26–e50.
Available at:
https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2019/01/chronic-hypertension-in-pregnancy
2. American College of Obstetricians and Gynecologists. Practice Bulletin No. 222: Gestational Hypertension and Preeclampsia.
Obstet Gynecol. 2020;135(6):e237–e260.
PMID: 32443079
3. ACOG Committee Opinion No. 692: Emergent Therapy for Acute-Onset, Severe Hypertension During Pregnancy and the Postpartum Period.
Details labetalol, hydralazine, and nifedipine regimens for acute management.
4. Croke L. Managing chronic hypertension in pregnant women. Am Fam Physician. 2019;100(12):782–783.
Summarizes labetalol, nifedipine ER, methyldopa, and hydrochlorothiazide dose ranges in pregnancy.
5. Tita ATN, et al.; CHAP Trial Consortium. Treatment for Mild Chronic Hypertension during Pregnancy.
N Engl J Med. 2022;386:1781–1792.
PMID: 35363951
6. Donel S, et al. Effectiveness of nifedipine, labetalol, and hydralazine as emergency antihypertensive drugs in severe preeclampsia.
Pregnancy Hypertens. 2023.
PMCID: PMC10238817
7. Caton AR, et al. Antihypertensive medication use during pregnancy and the risk of cardiovascular malformations.
Obstet Gynecol. 2009;113(3):540–546. Notes contraindication of ACE inhibitors and ARBs in pregnancy.
PMCID: PMC4913772
8. UK Teratology Information Service (UKTIS). Use of angiotensin-converting enzyme inhibitors in pregnancy.
Describes ACE-I fetopathy, including renal dysgenesis and skull ossification defects.
https://uktis.org/monographs/use-of-angiotensin-converting-enzyme-inhibitors-in-pregnancy/
9. Countouris ME, et al. Hypertension in Pregnancy and Postpartum.
Circulation. 2025;141:e???–e???. Contemporary review of antihypertensive therapy options and algorithms in pregnancy.
10. Additional dosing and safety details from standard obstetric and internal medicine references summarizing labetalol, nifedipine,
methyldopa, hydralazine, and thiazide diuretic use in pregnant patients with hypertension.