This sheet talks about exposure to antiviral medications in pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare providers.
What are antiviral medications and what do they do?
Antiviral medications are used to treat viral illnesses. This fact sheet focuses on antiviral medications that are 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/pdf/.
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 the antiviral medications used for influenza prevention and treatment. Currently the CDC recommends the use of oral oseltamivir for treatment of the flu during pregnancy. Your healthcare provider will need to give you a prescription, and they can confirm what medication is currently recommended and what would be best for you.
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. Pregnant individuals are at an increased risk of 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/pdf/.
I am taking an antiviral medication. Can it make it harder for me to get pregnant?
There are no studies that look at fertility in people taking an 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 can occur in any pregnancy. Researchers did not find a higher chance of miscarriage following the use of oseltamivir. The risk of miscarriage has not been studied for other antiviral medications.
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 have looked at the use of oseltamivir and zanamivir during pregnancy did not find an increased chance for birth defects. There are no studies looking at the use of peramivir and baloxavir in pregnancy.
Could taking an antiviral medication cause other pregnancy complications?
Several studies have not found a higher chance for pregnancy complications when oseltamivir or zanamivir was used during pregnancy. There are no studies looking at the use of peramivir and baloxavir.
Does taking an antiviral medication in pregnancy cause long-term problems in behavior or learning for the baby?
There are no studies that have looked at this question. Therefore, it is not known if antiviral medications could increase the chance for long-term problems.
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?
Talk with your healthcare provider if you have been in close contact with someone who has the flu. Because people who are pregnant are at an increased risk for complications from the flu, some individuals may benefit from taking antiviral medications, to prevent getting the flu after they have been exposed. Your healthcare provider can help you decide whether taking an antiviral medication for flu prevention is best for you.
Be sure that you and others around you are doing the following to help prevent spread of the flu:
- 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 year
Can I breastfeed while taking an antiviral medication?
Oseltamivir is found in breast milk in very low amounts (less than 1% of the breastfeeding person’s dose). Zanamivir is given by inhalation. This limits the amount of the medication that gets into the bloodstream. For this reason, zanamivir is unlikely to enter breast milk in high amounts. There have been no studies looking at the use of peramivir during breastfeeding. Because peramivir is poorly absorbed from the gut, it is unlikely that any medication that gets into the breast milk would enter the baby’s system. There are no studies looking at baloxavir during breastfeeding, and the CDC does not recommend its use while breastfeeding. Be sure to talk to your healthcare provider about all your breastfeeding questions.
I am taking an antiviral medication. Can it make it harder for me to get my 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/pdf/.
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