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Mother To Baby | Fact Sheets [Internet]. Brentwood (TN): Organization of Teratology Information Specialists (OTIS); 1994-.
Published online: February 2024.
This sheet is about exposure to antiviral medications 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 are antiviral medications and what do they do?
Antiviral medications treat viral illnesses. This fact sheet focuses on antiviral medications used to treat influenza (the “flu”). Symptoms of influenza may include fever, headache, chills, muscle aches, coughing, congestion, runny nose, and sore throat. Some people can also have stomach upset with vomiting and diarrhea. For more information, see the MotherToBaby fact sheet on Seasonal Influenza (the Flu) at https://mothertobaby.org/fact-sheets/seasonal-influenza-the-flu-pregnancy/.
Antiviral medications can lessen the symptoms of the flu and reduce the risk of serious illness. Some of these medications may also be used to prevent a person from catching the flu. These medications can be given as an oral tablet (pill), liquid suspension, intravenously (IV), or as an inhaled powder.
Oseltamivir (Tamiflu®), peramivir (Rapivab®), zanamivir (Relenza®), and baloxavir (Xofluza®) are some examples of antiviral medications used for influenza prevention and treatment. You need a prescription from your healthcare provider to get these medications. Your healthcare provider can discuss if and what medication is best for you.
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 this medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.
Can I skip getting the flu vaccine and just take one of these medications if I happen to get sick?
Antiviral medications are not a substitute for the flu vaccine. People who are pregnant have a higher chance for complications from the flu. People who are pregnant or planning to become pregnant should get the injected form of the flu vaccine (flu shot). The nasal-spray form of the influenza vaccine is not recommended during pregnancy. For more information, see the MotherToBaby fact sheet on the Seasonal Influenza Vaccine (Flu Shot) at https://mothertobaby.org/fact-sheets/seasonal-influenza-vaccine-flu-shot-pregnancy/.
I take an antiviral medication. Can it make it harder for me to get pregnant?
There are no studies that look at fertility in people taking antiviral medication.
I just found out I am pregnant. Should I stop taking an antiviral medication?
Talk with your healthcare providers before making any changes to how you take this medication. Because people who are pregnant have an increased chance of developing serious complications from the flu, your healthcare provider may recommend finishing your course of treatment if you have already started.
Does taking an antiviral medication increase the chance for miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. Researchers did not find a higher chance of miscarriage following the use of oseltamivir. As there can be many causes of miscarriage, it is hard to know if a medication, the medical condition, or other factors are the cause of a miscarriage. Studies have not been done to see if other antiviral medications increase the chance for miscarriage.
Does taking an antiviral medication 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. Several studies that looked at the use of oseltamivir and zanamivir during pregnancy did not find an increased chance for birth defects. Studies have not been done to see if peramivir or baloxavir increase the chance of birth defects.
Does taking an antiviral medication in pregnancy increase the chance of other pregnancy related problems?
Several studies have not found a higher chance for pregnancy complications with oseltamivir or zanamivir use during pregnancy. Studies have not been done to see if permavir or baloxivir increases the chance for other 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).
Does taking an antiviral medication in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if antiviral medications can cause behavior or learning issues for the child.
I am pregnant and think I may have the flu. Should I talk to my healthcare provider about starting an antiviral medication?
Yes. You should talk to your healthcare provider as soon as possible. People who are pregnant have a greater chance for complications from the flu. Some of these complications can put both the person who is pregnant and the developing baby at serious risk. Taking an antiviral medication within 48 hours (the earlier the better) of your first symptoms can reduce the chance of severe complications from the flu. The medications may still be helpful when they are started later than this, so talk to your healthcare provider even if you have already been sick for more than 2 days. For current recommendations regarding prevention and treatment of flu with antiviral medications visit the Centers for Disease Control and Prevention (CDC)’s website at https://www.cdc.gov/flu/treatment/whatyoushould.htm#pregnant-women.
I am pregnant and my partner has the flu. Should I take an antiviral medication so that I don’t get sick?
Wash your hands with soap and water frequently Avoid touching your eyes, nose, or mouth Try to avoid close contact with sick people Cover your nose and mouth when you cough or sneeze Stay home and avoid close contact with others if you are sick Get your flu shot every yearBreastfeeding while taking an antiviral medication:
Oseltamivir gets in breast milk in small amounts (less than 1% of the breastfeeding person’s dose). It has not been known to cause problems for nursing babies. Zanamivir is given by inhalation. This limits the amount of medication that gets into the bloodstream. For this reason, zanamivir is unlikely to enter breast milk in high amounts. Studies have not been done to see if the use of peramivir during breastfeeding would cause any effects to the baby. Because peramivir does not get absorbed well from the gut, it is unlikely that any medication that gets into the breast milk would enter the baby’s system. Studies have not been done to see if the use of baloxavir during breastfeeding would cause any effects to the baby. Be sure to talk to your healthcare provider about all your breastfeeding questions.
If a male takes an antiviral medication, could it affect fertility (ability to get partner pregnant) or increase the chance of birth defects?
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 on Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
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“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.
Copyright by OTIS, February 2024.This work is available under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported license (CC BY-NC-ND 3.0)
