Metoprolol

Last Update: 03 Aug 2026

Table of content

1. What is it? 2. What are the risks according to research? 3. Breastfeeding/ chestfeeding 4. What about fathers and sperm donors? 5. Key points

Welcome to our fact sheet on metoprolol during pregnancy and lactation. This information is based on available published literature. It should not take the place of medical care and advice from your healthcare provider.

The HEALTHY PREGNANCY HUB team is collaborating with MotherToBaby to share information on this topic. The original version is available here (January 2026).

Serene, our chatbot, can also answer your questions about medications during pregnancy.

Please note that this fact sheet is based on the one from MotherToBaby with United States information and has been reviewed by our Canadian experts. Minor differences may exist between the two countries. Always consult your healthcare professional for information tailored to your situation.

1. What is metoprolol?

Metoprolol is a medication that can be used to treat high blood pressure, a fast heart rate, and prevent migraines. It is part of a class of medications known as beta-blockers. Some brand names for metoprolol are Lopressor®, Toprol®, and Betaloc®.

Sometimes when people find out they are pregnant, they think about changing how they take their medication or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take your medication. Having high blood pressure can increase the chance of preterm delivery and low birth weight. In addition, high blood pressure in pregnancy can increase the chance of developing preeclampsia (high blood pressure and problems with organs, such as the kidneys) that can lead to seizures (called eclampsia). Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.

2. What does research say about the safety during pregnancy?

I take metoprolol. Can it make it harder for me to get pregnant?

It is not known if taking metoprolol can make it harder to get pregnant.

Does taking metoprolol increase the chance of miscarriage?

Miscarriage is common and can occur in any pregnancy for many different reasons. Studies have not been done to see if metoprolol can increase the chance of miscarriage.

Does taking metoprolol increase the chance of birth defects?

Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like metoprolol, might increase the chance of birth defects in a pregnancy.

It is not known if metoprolol increases the chance of birth defects. Animal studies have not reported an increased chance of birth defects. A large analysis of multiple studies in humans found that beta-blockers in general did not increase the chance of major birth defects.

Does taking metoprolol in pregnancy increase the chance of other pregnancy-related problems?

Metoprolol has been associated with intrauterine growth restriction (less growth of the fetus than expected). It is hard to know if a medication, the medical condition being treated, or other factors (such as age, health, other exposures) could be the cause of the growth restriction.

Metoprolol use in late pregnancy might cause the baby to have symptoms such as a slowed heart rate and low blood sugar near delivery. Talk with your healthcare providers about your use of metoprolol so that if symptoms occur, your baby can get the care that is best for them.

Does taking metoprolol in pregnancy affect future behavior or learning for the child?

Studies have not been done to see if metoprolol can increase the chance of behaviour or learning issues for the child.

3. Lactating while taking metoprolol:

Metoprolol passes into human milk in small amounts. Studies on the use of metoprolol during breast/chest feeding have not reported side effects in nursed infants. If you suspect the baby has any symptoms (such as slow heart rate, being too sleepy, having trouble with feeding, or pale skin), contact the child’s healthcare provider. Be sure to talk to your healthcare provider about all your breast/chest feeding questions.

4. What about fathers and sperm donors?

If a male takes metoprolol, could it affect his fertility or increase the chance of birth defects?

It is not known if metoprolol could affect male fertility (ability to make healthy sperm) or increase the chance of birth defects. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. In general, exposures that fathers and sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures here.

Key points

Metoprolol is a medication from the beta-blocker family used for high blood pressure, rapid heart rate, migraines, and other health conditions.
It is not known whether metoprolol affects fertility, increases the risk of miscarriage, or affects a child’s behaviour or learning later in life.
Current studies do not show that metoprolol increases the risk of birth defects, but more research is needed.
Metoprolol may slow a baby’s growth and development during pregnancy.
When taken near the end of pregnancy, metoprolol may cause temporary symptoms in the newborn, such as a slower heart rate or lower blood sugar levels.
Metoprolol passes into breast milk in small amounts, but studies have not reported side effects in breastfed infants.
Always talk with a healthcare professional before changing or stopping any medication.

References

Please click here for references.

Disclaimer

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