This sheet is about exposure to respiratory syncytial virus (RSV) in pregnancy or while breastfeeding. This information is based on published research studies. It should not take the place of medical care and advice from your healthcare provider.
What is respiratory syncytial virus (RSV)?
Respiratory syncytial virus (called RSV) is a common respiratory virus that usually causes mild, cold-like symptoms. Babies, older adults, and people with a weakened immune system have a higher chance of getting severe symptoms. Severe symptoms can include lower respiratory disease and pneumonia. People with severe symptoms might need to be treated in a hospital. It is not known if pregnant women have a higher chance of developing severe symptoms.
In most regions of the United States, RSV season generally starts during fall and peaks in the winter. However, the timing and severity of RSV seasons can be different from year to year and in different areas of the United States.
Is RSV contagious? How does the virus spread?
RSV spreads easily from person to person when someone who is infected with the virus coughs or sneezes. RSV can also be spread through direct contact with people who are sick (shaking hands or kissing) or touching surfaces that have the virus on them. Close contact with young children, such as in daycare settings, is a common way to become infected with RSV.
People infected with RSV usually show symptoms within 4 to 6 days after getting infected, but some people might not have symptoms (asymptomatic). People with RSV may be contagious 1 or 2 days before symptoms start, and most people are contagious for 3 to 8 days after symptoms start. However, some infants, and people with weakened immune systems, can still spread the virus for up to 4 weeks after they stop showing symptoms.
I have an RSV infection. Can it make it harder for me to get pregnant?
Studies have not been done to see if having an RSV infection could make it harder to get pregnant.
Does having RSV increase the chance of miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. One study reported that RSV was more common among women who had a miscarriage compared to women who did not have a miscarriage. However, other reports do not suggest a higher chance of miscarriage. As there can be many causes of miscarriage, it is hard to know if the infection, medication, or other factors are the cause of a miscarriage.
Does having RSV 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 RSV, might increase the chance of birth defects in a pregnancy. RSV infection in pregnancy is not well-studied. However, RSV is not expected to increase the chance of birth defects.
Would having RSV increase the chance of other pregnancy-related problems?
In reports of RSV in pregnancy, pregnancy complications such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth) were not common. In reports when a pregnancy complication was reported, many of those women also had another medical condition or infection.
If I have RSV during my pregnancy, can the infection pass to the fetus?
Studies have suggested that it is possible to pass an RSV infection to the fetus across the placenta. One small study reported that newborns born to women who had RSV during the third trimester could have some breathing problems related to RSV.
Does having RSV in pregnancy affect future behavior or learning for the child?
It is not known if RSV infection in pregnancy can affect future behavior or learning for the child.
How can I protect myself and my pregnancy?
The Centers for Disease Control and Prevention (CDC) recommend women who are pregnant get a single dose of the RSV vaccine during weeks 32 through 36 of pregnancy if they have not received an RSV vaccine in previous pregnancies. MotherToBaby has a fact sheet on the RSV vaccine at: https://mothertobaby.org/fact-sheets/respiratory-syncytial-virus-rsv-vaccine-abrysvo/.
In addition to getting the RSV vaccine, be sure that you and others around you are doing the following to help prevent spread of viruses:
- Wash your hands with soap and water often or use an alcohol-based hand sanitizer if soap and water are not available.
- Cover your nose and mouth when you cough or sneeze and ask those around you to do the same.
- Do not touch your eyes, nose, or mouth.
- Try to avoid close contact with people who are sick.
- Do not share drinking glasses or eating utensils with others.
- Clean touched surfaces such as doorknobs, toys, and mobile devices.
Breastfeeding while I have RSV:
Women are encouraged to keep breastfeeding even if they have RSV. Breast milk from someone who has RSV or had it during pregnancy might contain protective antibodies. This can help lower the baby’s risk of getting RSV or having severe symptoms. Be sure to talk to your healthcare provider about all your breastfeeding questions.
While sick, it is important to try to protect the baby from the virus. Wash hands with soap and water before holding your baby. Avoid coughing or sneezing on your baby. Cover your mouth/nose with a tissue when you cough or sneeze, then throw away the tissue and wash your hands.
If a man has RSV, can it make it affect fertility or increase the chance of birth defects?
Studies have not been done to see if RSV could affect male fertility (ability to get a woman pregnant) or increase the chance of birth defects. Close contact may not be recommended when you have RSV to try to avoid passing RSV to your partner. For more general information on paternal exposures, please see the MotherToBaby fact sheet at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
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