Is Labetalol Safe in Pregnancy? What the Guidance Actually Says

If you take labetalol for high blood pressure and you are pregnant or planning to be, you may be worried about whether the medicine could affect your baby. Here the news is often reassuring: labetalol is one of the blood-pressure medicines clinicians frequently choose during pregnancy, precisely because it has a long track record in this setting. This article gathers what leading sources say so you can have a more informed conversation with the clinician who manages your pregnancy. It is general education only and is not a substitute for that conversation.

What labetalol is and what it treats

Labetalol is a medication used to treat high blood pressure, and sometimes chest pain. It belongs to a group of medicines called beta-blockers, and it works by slowing the heart rate and relaxing blood vessels so that blood flows more easily and pressure comes down. In pregnancy it is used both for ongoing (chronic) high blood pressure and for high blood pressure that arises during pregnancy, including in some hypertensive disorders of pregnancy.

What the guidance says about labetalol in pregnancy

Labetalol stands out from many medicines in that it is often actively recommended in pregnancy rather than merely tolerated. Professional guidance, including from the American College of Obstetricians and Gynecologists (ACOG) as summarized in the medical literature, recognizes labetalol as one of the first-line, preferred oral medicines for managing high blood pressure in pregnancy, alongside options such as nifedipine. Clinicians often treat these agents as broadly interchangeable choices, selecting based on the individual patient.

Birth defects

MotherToBaby, a service of the non-profit Organization of Teratology Information Specialists, reports that available information does not suggest that the use of labetalol in pregnancy increases the chance of birth defects.

Miscarriage and blood pressure control

On miscarriage, MotherToBaby is candid that it is not known whether labetalol itself increases the chance of miscarriage. Importantly, it adds that high blood pressure that is not well managed might itself increase the chance of miscarriage. In other words, the underlying condition, if left uncontrolled, is a source of risk, which is part of why treatment is emphasized.

Effects on the newborn

MotherToBaby notes that temporary symptoms have been reported in some infants exposed to labetalol late in pregnancy. These can include a slowed heart rate, low blood pressure, and low blood sugar, and it notes such effects have been described particularly in some preterm infants exposed over a longer period. In most cases these symptoms resolve within a few days. Because of this, babies exposed near delivery may be watched a little more closely at first. This is a reason for monitoring, not usually a reason to avoid a needed medicine.

The other side: untreated high blood pressure is dangerous

It is important not to read any caution as a reason to stop treatment. Poorly controlled high blood pressure in pregnancy is associated with serious risks to both parent and baby, including complications such as pre-eclampsia, problems with the baby’s growth, and preterm birth. This is a major reason clinicians treat elevated blood pressure in pregnancy rather than leaving it alone, and why medicines with a good track record in pregnancy, such as labetalol, are used. The goal of care is safe, effective blood-pressure control, not avoiding all medicine.

Do not stop a beta-blocker on your own

This point deserves emphasis. Beta-blockers such as labetalol should not be stopped suddenly on your own, because abruptly stopping a beta-blocker can, in some people, lead to a rebound rise in blood pressure or heart-related effects. On top of that, uncontrolled high blood pressure is itself risky in pregnancy. If you are worried about your medicine, the safe move is to talk with the prescriber who manages it rather than pausing it yourself. Any change in dose or medication should be made with your clinician, who can adjust things safely.

A note on drug “categories”

You may see older references sorting pregnancy medicines into letter categories such as A, B, C, D, and X. Those FDA letter categories have been retired. They were replaced with a narrative labeling system (the Pregnancy and Lactation Labeling Rule) that describes what is actually known from studies rather than assigning a single letter. If you come across an old “category” for labetalol, treat it as outdated and rely on current guidance and your care team.

Breastfeeding

MotherToBaby reports that labetalol passes into breast milk in small amounts, and that these amounts are not expected to cause problems in full-term breastfed infants. As always, mention any medication to your clinician, especially if your baby was born early or has health concerns, and report anything that seems unusual.

When to call your OB or a specialist

Contact your obstetric provider promptly if you have very high blood pressure readings, a severe headache, changes in vision, swelling that comes on suddenly, upper-abdominal pain, or reduced fetal movement later in pregnancy, as these can be signs of a hypertensive complication that needs urgent care. If your blood pressure is difficult to control, your provider may involve a maternal-fetal-medicine specialist. For questions about a specific medication exposure in pregnancy or breastfeeding, you can also call MotherToBaby at 1-866-626-6847, a free service that answers questions about medicines and other exposures.

Frequently asked questions

Is labetalol safe to take while pregnant? Labetalol is widely regarded as one of the preferred blood-pressure medicines in pregnancy, and MotherToBaby reports that available information does not suggest it increases the chance of birth defects. Whether it is right for you is a decision for your care team.

Why do doctors often choose labetalol in pregnancy? It has a long track record for controlling high blood pressure in pregnancy, and professional guidance recognizes it as a first-line option alongside medicines such as nifedipine. Controlling blood pressure protects both parent and baby.

Can I just stop labetalol if I’m worried? No. Beta-blockers should not be stopped abruptly on your own, and uncontrolled high blood pressure is itself risky in pregnancy. Talk to your prescriber before making any change.

Will labetalol affect my baby at birth? Some babies exposed late in pregnancy have temporary effects such as a slower heart rate, lower blood pressure, or low blood sugar, which usually resolve within a few days. Babies exposed near delivery may be monitored a little more closely.

Can I breastfeed while taking labetalol? MotherToBaby reports only small amounts pass into breast milk and problems are not expected in full-term infants. Confirm with your clinician, particularly for a baby born early.

What if my blood pressure is still high on labetalol? Contact your provider. They may adjust the dose or add or change medicines. Do not adjust the dose yourself.

Sources

• MotherToBaby (Organization of Teratology Information Specialists) — Labetalol fact sheet.
• American College of Obstetricians and Gynecologists (ACOG) — guidance recognizing labetalol and nifedipine as first-line antihypertensives in pregnancy, as summarized in peer-reviewed literature.
• Peer-reviewed comparisons of labetalol for chronic hypertension in pregnancy, located via PubMed/NCBI.