Antihypertensive Agents in Pregnancy

FOR USE BY MEDICAL PROFESSIONALS. Verify dosing with current labeling and your institution’s OB safety-bundle/order sets. Individualize therapy based on gestational age, diagnosis (chronic HTN vs gestational HTN vs preeclampsia), and comorbidities (asthma, bradycardia/heart block, renal/hepatic disease).

Quick index

Definitions & key thresholds

Severe-range (acute-onset) hypertension Sustained SBP ≥ 160 and/or DBP ≥ 110 mmHg is treated urgently with fast-acting agents; pathways typically aim to reduce stroke risk while avoiding hypotension.
After initial control, many protocols target about 130–150 / 80–100 and continue close monitoring.
Chronic hypertension — treatment threshold Contemporary guidance increasingly supports initiating or titrating therapy for chronic hypertension in pregnancy at approximately BP ≥ 140/90 (rather than waiting for severe-range values), with individualized targets and follow-up.

Chronic blood pressure control (maintenance)

General approach (maintenance)
  • First-line (common) Labetalol and nifedipine ER are frequently used.
  • Alternatives Methyldopa and selected beta-blockers (e.g., metoprolol/propranolol) may be used for specific indications or intolerance to first-line agents; oral hydralazine and thiazides are used selectively.
  • Confirm home BP technique, assess symptoms, review meds that raise BP (NSAIDs postpartum, stimulants), and plan fetal surveillance per chronic HTN pathway.
“How supplied” details in link to DailyMed/FDA search.

Chronic / non-severe hypertension — common oral options (table)

At-a-glance Dose ranges and comments adapted from Perinatology.com OBPharm (public) antihypertensives table.

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.
BP targets (context): Many pathways now treat mild chronic HTN to maintain < 140/90 (patient-specific).

Labetalol (oral) — maintenance

Common first-line Mixed α/β blocker used for chronic HTN control in pregnancy and postpartum.

How administered
Oral tablets (divided dosing; titrate to BP).
Typical use
Chronic hypertension maintenance; postpartum continuation if needed.

Dose/titration vary widely; use your institutional pathway and current labeling.

How supplied
Package insert / labeling
DailyMed: labetalol (search)  |  FDA Drugs@FDA search
Key cautions
Asthma/bronchospasm Bradycardia/heart block Monitor maternal HR/BP.

Nifedipine extended-release (ER) — maintenance

Common first-line Calcium channel blocker; ER formulation used for chronic BP control.

How administered
Oral ER tablets/capsules (once daily; titrate).
Typical use
Chronic hypertension maintenance in pregnancy and postpartum.

Use ER for maintenance. IR nifedipine is typically reserved for acute severe-range treatment in algorithms.

How supplied
Package insert / labeling
DailyMed: nifedipine ER (search)
Key cautions
Headache/flushing/edema; avoid overshoot hypotension.

Hydralazine (oral) — maintenance (selected patients)

Adjunct / alternative Less common for maintenance than labetalol/nifedipine ER; consider when preferred agents are not suitable.

How administered
Oral tablets (typically divided dosing; titrate).
Typical use
Alternative/adjunct maintenance agent.

Dosing is individualized; confirm with your protocol and labeling.

How supplied
Package insert / labeling
DailyMed: hydralazine (search)
Key cautions
Tachycardia, headache/flushing; rare drug-induced lupus with longer-term use (label).

Methyldopa — maintenance (alternative)

Alternative Long history in pregnancy; often limited by sedation/tolerability.

How administered
Oral tablets (divided dosing; titrate).
Typical use
Alternative maintenance agent when first-line agents are not suitable or tolerated.
How supplied
Package insert / labeling
DailyMed: methyldopa (search)
Key cautions
Sedation, depression; rare hepatotoxicity/hemolytic anemia (label).

Metoprolol — maintenance (selected use)

Selected use β1-selective blocker often used for maternal arrhythmias; may be used for BP control when clinically appropriate.

How administered
Oral (immediate-release or extended-release depending on product); IV exists but not typical first-line for OB severe HTN pathways.
Typical use
Consider when there is a coexisting indication (e.g., tachyarrhythmia) or intolerance to first-line chronic HTN agents.

Prefer agents with the best obstetric evidence for primary HTN control (commonly labetalol or nifedipine ER). Use local protocol.

How supplied
Package insert / labeling
DailyMed: metoprolol (search)
Key cautions
Bradycardia/heart block Neonatal effects Possible neonatal bradycardia/hypoglycemia with late pregnancy exposure (class effect—monitor per nursery protocol).

Propranolol — maintenance (selected use)

Selected use Nonselective beta-blocker; more commonly used for migraine/thyrotoxicosis/arrhythmia than primary chronic HTN control in pregnancy.

How administered
Oral (IR or ER formulations); IV exists (non-OB first-line for severe HTN).
Typical use
Consider when there is a compelling indication (e.g., thyrotoxicosis symptom control, certain arrhythmias, migraine prophylaxis) and BP benefit is desired.

Because it is nonselective, avoid in patients with reactive airway disease when possible.

How supplied
Package insert / labeling
DailyMed: propranolol (search)
Key cautions
Asthma/bronchospasm Bradycardia Neonatal effects Potential neonatal bradycardia/hypoglycemia with late pregnancy exposure (class effect—monitor per nursery protocol).

Hydrochlorothiazide (HCTZ) — maintenance (selected patients)

Selected use Low-dose thiazide can be continued in selected patients (especially if effective pre-pregnancy); monitor volume status and electrolytes.

How administered
Oral tablets/capsules.
Usual dose (non-severe chronic HTN table)
12.5–25 mg orally once daily.

Avoid volume depletion; monitor electrolytes and renal function as clinically indicated.

How supplied
Package insert / labeling
DailyMed: hydrochlorothiazide (search)
Key cautions
Volume depletion Electrolytes Use cautiously with vomiting/poor intake/diarrhea; reassess if hypotension or rising creatinine.

Acute severe-range hypertension (pregnancy & postpartum)

Fast-acting first-line options (common safety-bundle pathways) IV labetalol, IV hydralazine, or PO nifedipine immediate-release are commonly used.

Labetalol (IV) — acute control

First-line option Avoid as first choice with bronchospasm/asthma or marked bradycardia/heart block.

How administered
IV push for over more than 2 minutes (per algorithm), repeat/titrate per response.
Example severe-range algorithm dosing
  • 20 mg IV → reassess in 10 minutes
  • If still ≥160/110: 40 mg IV over more than 2 minutes → reassess in 10 minutes
  • If still ≥160/110: 80 mg IV over more than 2 minutes → reassess in 10 minutes
  • If still ≥160/110: Administer hydralazine 10 mg IV over more than 2 minutes → reassess in 20 minutes
  • If still ≥160/110: Obtain emergency consultation MFM or critical care

Proceed per protocol if persistent severe-range BP.


How supplied
Labeling
DailyMed: labetalol injection (search)

Hydralazine (IV) — acute control

First-line option Common alternative if β-blockade is undesirable (e.g., asthma/bradycardia).

How administered
  • 5 or 10 mg IV over more than 2 minutes → reassess in 20 minutes
  • If still ≥160/110: 10 mg IV over more than 2 minutes → reassess in 20 minutes
  • If still ≥160/110: Administer labetalol 20 mg IV over more than 2 minutes. Obtain emergency consultation with MFM or critical care. → reassess in 10 minutes
  • If still ≥160/110: Administer labetalol 40 mg IV over more than 2 minutes.

Proceed per protocol if persistent severe-range BP.

 

How supplied
Labeling
DailyMed: hydralazine injection (search)

Nifedipine immediate-release (IR, PO) — acute control

First-line option Useful when IV access is delayed/unavailable. Avoid non-protocol sublingual use.

How administered
Oral IR capsule/tablet per protocol.
Example severe-range algorithm dosing
  • 10 mg PO (IR) → reassess in 20 minutes
  • If still ≥160/110: 20 mg PO (IR) → reassess in 20 minutes
  • If still ≥160/110: 20 mg PO (IR) → reassess in 20 minutes
  • If still ≥160/110: Administer labetalol 20 mg IV over more than 2 minutes. Obtain emergency consultation with MFM or critical care. → reassess in 10 minutes
  • If still ≥160/110: Administer labetalol 40 mg IV over more than 2 minutes.

Proceed per protocol if persistent severe-range BP.


How supplied
Labeling
DailyMed: nifedipine IR (search)

Agents to avoid in pregnancy (typical)

Avoid Generally avoided in pregnancy due to fetal/newborn risks (confirm with current guidance):

  • ACE inhibitors (e.g., lisinopril, enalapril)
  • ARBs (e.g., losartan)
  • Direct renin inhibitors (e.g., aliskiren)
  • Mineralocorticoid receptor antagonists (e.g., spironolactone) — generally avoided

Postpartum/breastfeeding choices can differ; use lactation-specific references and local protocols.

OBPharm/OBRx disclaimer THE INFORMATION IN THE OBPHARM/OBRx CONTENT IS INTENDED SOLELY FOR USE BY THE MEDICAL PROFESSION. IT IS NOT INTENDED FOR LAY PERSONS. The prescribing physician must be familiar with full product labeling and relevant medical literature prior to use.

UPDATED: 12/18/2025

References (click to expand)

References

  1. ACOG Committee Opinion No. 767 (2019): Emergent therapy for acute-onset, severe hypertension during pregnancy and postpartum (interim update). PDF
  2. Acute Hypertension in Pregnancy and Postpartum Algorithm (state perinatal quality collaborative toolkit; step-dosing examples). PDF
  3. PDR.net for “How Supplied” (product forms/strengths): PDR home
  4. DailyMed (NLM) for manufacturer labeling/package inserts: DailyMed home

Note: Beta-blockers (including metoprolol and propranolol) may be used in pregnancy for selected indications; monitor for fetal growth issues and neonatal bradycardia/hypoglycemia risk, particularly with exposure near delivery (class effect). Always verify with current guidance and local protocols.