This sheet is about exposure to molnupiravir in pregnancy and while breastfeeding. This information is based on available published literature. It should not take the place of medical care and advice from your healthcare provider.

What is molnupiravir?

Molnupiravir is an antiviral medication that has been given emergency permission by the U.S. Food and Drug Administration (FDA) to treat mild to moderate COVID-19 in certain patients. Molnupiravir must be started within 5 days of having symptoms of COVID-19 in order to be effective. A brand name for molnupiravir is Lagevrio®.

The FDA emergency use guidelines for molnupiravir recommend people who are pregnant not use this medication unless there are no other treatment options and treatment is clearly needed. This is because there is not enough information available on the use of molnupiravir to know if/how it could affect a pregnancy. However, the benefit of using molnupiravir may outweigh possible risks. Your healthcare provider can talk with you about using molnupiravir and what treatment is best for you. For more information about COVID-19, please the see the MotherToBaby fact sheet at https://mothertobaby.org/fact-sheets/covid-19/.

I am taking molnupiravir, but I would like to get pregnant after taking it. How long does the drug stay in my body?

People eliminate medication at different rates. In non-pregnant adults, it takes up to 1 day, on average, for most of the molnupiravir to be gone from the body. The FDA emergency use guidelines recommend that females avoid trying to get pregnant while they are taking molnupiravir and for 4 days after the last dose.

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

It is not known if molnupiravir can make it harder to get pregnant. The FDA emergency use guidelines recommend that females who can get pregnant use effective contraception correctly and consistently while they are taking molnupiravir and for 4 days after the last dose.

Does taking molnupiravir increase the chance of miscarriage?

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

Does taking molnupiravir increase the chance of birth defects?

Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Studies have not been done in humans to see if molnupiravir can increase the chance of birth defects above the background risk.

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

Studies have not been done in humans to see if molnupiravir can increase the chance of pregnancy-related problems such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth). Having COVID-19 during pregnancy can increase the chance of preterm delivery, stillbirth, and other pregnancy complications.

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

Studies have not been done to see if molnupiravir can cause behavior or learning issues for the child.

Breastfeeding while taking molnupiravir:

The FDA emergency use guidelines for molnupiravir recommend that people who are breastfeeding not use this medication unless there are no other treatment options and treatment is clearly needed. But the benefit of using molnupiravir along with the benefits of breastfeeding your baby may outweigh possible risks. People who are breastfeeding can consider pumping and discarding breast milk during treatment with molnupiravir and for 4 days after the last dose. Your healthcare providers can talk with you about using molnupiravir and what treatment is best for you. Be sure to talk to your healthcare provider about all your breastfeeding questions.

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

Studies have not been done to see if molnupiravir could affect male fertility (ability to get partner pregnant) or increase the chance of birth defects above the background risk. The FDA emergency use guidelines recommend that males use a reliable method of contraception correctly and consistently during treatment and for at least 3 months after the last dose of molnupiravir. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.

Selected References:

• DeSisto CL, et al. 2021. Risk of stillbirth among women with and without COVID-19 at delivery hospitalization - United States, March 2020 - September 2021. MMWR Morb Mortal Wkly Rep 70:1640-1645. [PMC free article: PMC8612508] [PubMed: 34818318]
• Kasehagen L, et al. 2021. COVID-19 - associated deaths after SARS-CoV-2 infection during pregnancy - Mississippi, March 1, 2020 - Octobera 6, 2021. MMWR Morb Mortal Wkly Rep 70:1646-1648. [PMC free article: PMC8612513] [PubMed: 34818319]
• Merck & Co., Inc. 2021. Center for Drug Evaluation and Research Antimicrobial Drugs Advisory Committee Meeting Briefing Document. Molnupiravir. Available at https://www​.fda.gov/media​/154421/download
• Regan AK, et al. 2022. SARS-CoV-2 infection during pregnancy and associated perinatal health outcomes: a national US cohort study. J Infect Dis 225(5):759-767. [PMC free article: PMC8755310] [PubMed: 34958090]
• U.S. Food & Drug Administration, Antimicrobial Drugs Advisory Committee. November 30, 2021. Molnupiravir. Available at https://www​.fda.gov/media​/154472/download
• U.S. Food & Drug Administration. 2021 (Revised October 2023). Fact Sheet for Healthcare Providers: Emergency Use Authorization for Molnupiravir. Available at https://www​.fda.gov/media​/155054/download

“OTIS/MotherToBaby encourages inclusive and person-centered language. While our name still contains a reference to mothers, we are updating our resources with more inclusive terms. Use of the term mother or maternal refers to a person who is pregnant. Use of the term father or paternal refers to a person who contributes sperm.