Labetalol
MedicationBeta-blocker
Research strength: 3 / 5
MotherToBaby says the available information is limited and does not suggest that labetalol increases the chance of birth defects. A 2026 French database study found an association between first-trimester labetalol and major birth defects compared with pregnancies without blood-pressure medicine, but not compared with calcium-channel blocker users. The comparison with calcium-channel blockers had wide confidence limits, so the study does not show whether labetalol caused the difference. A public summary of ACOG's 2019 bulletin lists labetalol as a preferred medicine for chronic high blood pressure; ACOG's advisory, reaffirmed in 2025, says treatment can begin at 140/90. Ask your provider about your situation.
Last reviewed: 2026-10-16
Sources
- MotherToBaby: Labetalol fact sheetTeratology service
- Delteil et al.: EFEMERIS first-trimester studyUS government
- American Family Physician: public summary of ACOG Practice Bulletin 203
- ACOG Practice Advisory: CHAP study guidanceProfessional society
- Tita et al.: CHAP randomized trialUS government
Research strength: 4 / 5
MotherToBaby says pregnancy research on labetalol is limited and does not give a separate second-trimester estimate. ACOG recommends starting or adjusting treatment for chronic high blood pressure at 140/90; a public summary of ACOG's 2019 bulletin lists labetalol and nifedipine as preferred medicines. Two 2026 head-to-head studies reported different maternal results, but neither found a clear difference in its composite fetal or newborn outcomes between labetalol and nifedipine. Neither study compared labetalol with no treatment, and both were observational. Ask your provider about your situation.
Last reviewed: 2026-10-16
Sources
- MotherToBaby: Labetalol fact sheetTeratology service
- ACOG Practice Advisory: CHAP study guidanceProfessional society
- American Family Physician: public summary of ACOG Practice Bulletin 203
- Tita et al.: CHAP randomized trialUS government
- Atkinson et al.: labetalol versus nifedipine comparisonUS government
- Psaras et al.: California comparative cohortUS government
Research strength: 3 / 5
MotherToBaby says some babies exposed to labetalol near delivery have temporary slow heart rate or low blood sugar that usually resolves within a few days. A large US study of late-pregnancy beta-blocker exposure, including labetalol, found higher rates of newborn low blood sugar and slow heart rate. A 2025 study found labetalol exposure at delivery was linked with low blood sugar at one hour, but not at 24 hours, bradycardia, or neonatal intensive care admission. The studies do not show which babies will have these effects. Ask your provider about your situation.
Last reviewed: 2026-10-16
Labetalol — Breastfeeding
Research strength: 3 / 5
MotherToBaby says labetalol reaches milk in small amounts and is not expected to affect full-term infants, while preterm infants warrant discussion with care teams. LactMed describes one report of slow heart rate in a very premature infant fed expressed milk while the mother took labetalol; it resolved after milk was replaced, but one case cannot show cause. The EMA says nipple pain and Raynaud's phenomenon of the nipple have been reported with labetalol; Raynaud's can cause reduced blood flow, numbness, pale skin, and pain. The EMA also said evidence on suppressed lactation was not strong enough for a product-label change and called for continued monitoring. Ask your provider about your situation.
Last reviewed: 2026-10-16
Pregnancy
MotherToBaby describes the pregnancy information as limited and says it does not suggest a higher chance of birth defects. In the French EFEMERIS database study, 1,813 pregnancies had beta-blocker exposure in the first trimester, 2,903 had calcium-channel-blocker exposure, and 172,284 had no antihypertensive exposure. The labetalol-specific adjusted odds ratio for major congenital anomalies was 2.00 (95% CI 1.06 to 3.40) versus no antihypertensive medicine and 1.06 (95% CI 0.37 to 3.48) versus calcium-channel-blocker exposure. The association was present against the untreated group but not against the active-comparator group; the latter estimate was imprecise, and the observational study cannot establish that labetalol caused the difference. ACOG's CHAP advisory, reaffirmed in March 2025, recommends starting or adjusting treatment for chronic hypertension at 140/90 rather than waiting for severe hypertension. The CHAP randomized trial enrolled 2,408 pregnant people before 23 weeks and found fewer primary composite outcomes with treatment than with waiting for severe hypertension, with no increase in small-for-gestational-age births; it tested a treatment strategy, not labetalol alone. A 2026 Australian target-trial emulation included 7,416 treated pregnancies and found no difference in its composite neonatal outcome between labetalol and nifedipine, while the nifedipine group had more maternal composite outcomes. A 2026 California Medicaid cohort of 2,281 singleton births found no clear difference in its composite maternal and fetal outcomes between labetalol and nifedipine. These comparative studies had different populations and outcome definitions, and neither compared labetalol with no treatment.
Breastfeeding
MotherToBaby and LactMed describe low amounts of labetalol in milk and do not expect adverse effects in most full-term infants; LactMed says another medicine may be preferred for a preterm infant. LactMed describes a case report of a very premature infant with slow heart rate after receiving expressed milk from a mother taking labetalol; the symptom resolved after the milk was replaced, and no other cause was identified. A 2024 prospective beta-blocker breastfeeding study interviewed 53 women, of whom 27 breastfed; no serious adverse event was observed, but the abstract did not report labetalol-specific outcomes. The EMA PRAC recommendation adopted in October 2021 added reports of nipple pain and Raynaud's phenomenon of the nipple to product information. It said evidence on suppressed lactation was not strong enough for a label change and should continue to be monitored.
Labetalol is a combined alpha- and beta-adrenergic blocker used to lower blood pressure.
What was tested
Pregnancy evidence includes observational database studies, a randomized trial of treatment for mild chronic hypertension that did not test labetalol alone, and active-comparator studies of antihypertensive medicines. Newborn evidence includes a large Medicaid cohort of beta-blocker exposure at delivery and a single-center cohort with 605 labetalol-exposed deliveries. Breastfeeding evidence includes small milk-level studies, individual case reports, and a 2024 prospective study of beta-blocker-treated patients that did not report labetalol-specific outcomes. The available designs cannot separate all effects of treatment from effects of the high blood pressure that led to treatment.
Does first-trimester labetalol increase the chance of major birth defects?
- Source A says
- MotherToBaby says the available information does not suggest that labetalol increases the chance of birth defects, while noting that pregnancy information is limited. (MotherToBaby: Labetalol fact sheet)
- Source B says
- The EFEMERIS study found an association between first-trimester labetalol and major congenital anomalies compared with no antihypertensive exposure (adjusted OR 2.00, 95% CI 1.06 to 3.40), but not compared with calcium-channel-blocker exposure (adjusted OR 1.06, 95% CI 0.37 to 3.48). (Delteil et al.: EFEMERIS beta-blocker and congenital anomaly study)
- Why they differ
- MotherToBaby summarizes earlier available information, while the EFEMERIS study is a newer observational comparison with both untreated and active-comparator groups. Hypertension and its severity can affect which medicine is used, and the active-comparator estimate has wide confidence limits.
- What the evidence shows overall
- The study raises a signal against the untreated group but does not establish that labetalol caused the difference. The active-comparator result was not statistically elevated, but its imprecision leaves uncertainty. More first-trimester evidence is needed.
How do labetalol and nifedipine compare for pregnancy outcomes?
- Source A says
- In an Australian target-trial emulation, nifedipine was associated with more maternal composite outcomes than labetalol, while the composite neonatal outcome did not differ. (Atkinson et al.: labetalol versus nifedipine target-trial emulation)
- Source B says
- In a California chronic-hypertension cohort, nifedipine and labetalol had similar adjusted composite outcomes and were described as equivalent in effectiveness and safety. (Psaras et al.: California oral antihypertensive cohort)
- Why they differ
- The Australian study included chronic hypertension, gestational hypertension, and preeclampsia from 11 to 36 weeks. The California study included chronic hypertension with treatment started by 23 weeks. Both were observational and used different populations and outcome definitions.
- What the evidence shows overall
- The studies do not establish a single best medicine for every pregnancy. They compare active treatments, not labetalol with no treatment, and do not replace ACOG's guidance on treating chronic hypertension.
- ACOG's advisory recommends starting or adjusting treatment for chronic hypertension in pregnancy at 140/90 rather than waiting for severe-range blood pressure. (ACOG)
- The public American Family Physician summary of ACOG Practice Bulletin 203 lists labetalol and extended-release nifedipine as preferred medicines for chronic hypertension in pregnancy. (American Family Physician)
- ACOG says patients already taking blood-pressure medicine when pregnancy begins can remain on it when there are no mitigating factors or side effects. (ACOG)
- The labetalol product label describes rare severe liver injury, including reported liver necrosis and death. (DailyMed)
General research, not specific to pregnancy.
The product label lists serious contraindications and warns about rare severe liver injury. A 2026 case report, systematic review, and FDA adverse-event analysis reported a liver-injury signal, but these reports do not measure how often it occurs.
- The label lists bronchial asthma or obstructive airway disease, overt cardiac failure, greater-than-first-degree heart block, cardiogenic shock, severe bradycardia, and prior hypersensitivity as contraindications. (DailyMed: labetalol hydrochloride tablet label)
- The label says severe hepatocellular injury occurs rarely and that hepatic necrosis and death have been reported. (DailyMed: labetalol hydrochloride tablet label)
- A 2026 review identified 27 published case reports and found a strong disproportionality signal in FDA adverse-event reports; the authors note that further population-based study is needed. (Hendriksen et al.: labetalol liver-injury case report and review)
- The label warns that abrupt withdrawal can worsen ischemic heart disease. (DailyMed: labetalol hydrochloride tablet label)
- MotherToBaby: Labetalol fact sheetTeratology serviceSecondary
- LactMed: LabetalolUS governmentSecondaryPage dated 2024-11-15Independent check
- DailyMed: labetalol hydrochloride tablet labelDrug company labelTertiaryPage dated 2026-09-11
- ACOG Practice Advisory: CHAP study guidanceProfessional societySecondaryPage dated 2025-03-01Independent check
- American Family Physician: public summary of ACOG Practice Bulletin 203SecondaryPage dated 2019-12-15
- Tita et al.: CHAP randomized trialUS governmentPrimaryPage dated 2022-04-02Independent check
- Delteil et al.: EFEMERIS beta-blocker and congenital anomaly studyUS governmentPrimaryPage dated 2025-11-14Independent check
- Atkinson et al.: labetalol versus nifedipine target-trial emulationUS governmentPrimaryPage dated 2026-06-05Independent check
- Psaras et al.: California oral antihypertensive cohortUS governmentPrimaryPage dated 2026-06-01Independent check
- Bateman et al.: late-pregnancy beta-blocker exposure studyUS governmentPrimaryPage dated 2016-09-01Independent check
- Berger et al.: peripartum antihypertensive cohortUS governmentPrimaryPage dated 2025-06-25Independent check
- Freppel et al.: beta-blockers and breastfeeding prospective studyUS governmentPrimaryPage dated 2024-09-11Independent check
- EMA PRAC: labetalol nipple pain and suppressed lactation signalEU agencySecondaryPage dated 2021-11-22Independent checkEuropean guidance
- Hendriksen et al.: labetalol liver-injury case report and reviewUS governmentPrimaryPage dated 2026-04-01Independent check
Last reviewed 2026-10-16
Independent check 2026-10-16
Not yet clinician-reviewed
Ask your provider about your situation.
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