This sheet is about exposure to seasonal influenza 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 influenza?
Influenza is an infection of the respiratory (breathing) tract. It is often called the flu. The symptoms of influenza are fever, headache, chills, muscle aches, coughing, congestion, runny nose, and sore throat. Influenza sometimes causes vomiting and diarrhea.
The typical flu season is from October through May of each year, and usually has the most activity between December and February. The types (strains) of viruses that cause seasonal influenza can change each year.
Is the flu contagious? How does the virus spread?
Yes, the flu is very contagious. The virus is spread through contact with respiratory droplets from the nose and mouth of infected individuals a day before they feel sick until their symptoms are gone. When people cough, sneeze, or talk, droplets containing the virus are spread through the air. These droplets can travel up to 6 feet from the person and can enter the mouth/noses of people nearby or fall and land on surfaces, such as tables and toys.
The time between exposure to a flu virus and the onset of symptoms (incubation period) is between 1 and 4 days. Adults who have the flu are most contagious in the first 3 to 4 days after their illness starts. Children can be infectious for a longer period.
Can having the flu make it harder for me to become pregnant?
Studies have not looked to see if having the flu will make it harder to become pregnant.
Does having the flu increase the chance of miscarriage?
Miscarriage can occur in any pregnancy. Some studies suggest a higher chance for pregnancy loss while other studies do not. Based on the available data, it is not known if the flu will increase the chance for miscarriage.
Can having the flu during pregnancy cause birth defects?
Every pregnancy starts out with a 3-5% chance of having a baby with a birth defect. This is called the background risk. Having the flu during pregnancy has not been proven to cause birth defects.
Fever is a possible symptom of the flu. A high fever in the first trimester can increase the chance of certain birth defects. Acetaminophen has been recommended to reduce fever in pregnancy. If you get sick with the flu or any other illness and develop a fever, talk with your healthcare provider to confirm if taking acetaminophen is okay for you. For more information about fever and pregnancy, see the related fact sheet at https://mothertobaby.org/fact-sheets/hyperthermia-pregnancy/, and for information on acetaminophen, please see https://mothertobaby.org/fact-sheets/acetaminophen-pregnancy/.
Does having the flu increase the chance for pregnancy complications?
Being pregnant can increase the chance of developing serious complications from the flu compared to persons with the flu who are not pregnant. Some of the serious complications reported include respiratory distress (severe breathing problems) and being hospitalized. If a person who is pregnant becomes very sick from the flu, this can also increase the chance of pregnancy complications, such as delivery before 37 weeks of pregnancy (preterm delivery). It is important to talk with your healthcare provider if you are pregnant and have symptoms of the flu.
Does having the flu cause long-term problems in learning and behavior for the baby?
Studies on long-term problems have looked at whether having the flu in pregnancy could lead to later mental health conditions like schizophrenia. These studies have not been able to prove that having the flu during pregnancy will increase the chance for the baby to later develop a mental health condition.
How can I protect myself and my baby?
The most important thing you can do for you and your baby is to get the flu shot. Because people who are pregnant have a greater chance for complications from the flu, individuals who are pregnant (whether in their first, second, or third trimester), or planning to become pregnant, should get the injected seasonal flu shot. A nasal-spray influenza vaccine is also available. This vaccine contains a live but weakened virus. The nasal-spray influenza vaccine is not recommended during pregnancy. For more information about the flu vaccines during pregnancy, see the MotherToBaby fact sheet on the Seasonal Influenza Vaccine (Flu Shot) at https://mothertobaby.org/fact-sheets/seasonal-influenza-vaccine-flu-shot-pregnancy/.
In addition to getting the flu shot, 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 often, or use an alcohol-based hand sanitizer if soap and water is not available
- Do not touch your eyes, nose, or mouth
- Try to avoid close contact with people who are sick
- Cover your nose and mouth when you cough or sneeze and ask those around you to do the same.
What should I do if I get sick?
If you have flu-like symptoms, call your healthcare provider right away. Your healthcare provider may recommend antiviral medications to lessen the symptoms of the flu and to reduce the chance of serious illness. These medications work best if taken early in the course of the illness. For more information about antiviral medications, see the MotherToBaby related fact sheet at https://mothertobaby.org/fact-sheets/antiviral-medications-treatprevent-influenza-the-flu-pregnancy/. If you are sick, stay home and avoid close contact with others to prevent passing the flu to other people.
Can I breastfeed if I have the flu?
The Centers for Disease Control and Prevention (CDC) encourages people to continue to breastfeed or provide breast milk for their babies even if they have the flu. There are antibodies in breast milk that might help prevent a baby from getting sick with the flu. 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 getting sick. 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. While you are ill, you may want to consider having someone who is not sick help you care for your baby. The CDC has more information on the flu and breastfeeding at https://www.cdc.gov/breastfeeding/breastfeeding-special-circumstances/maternal-or-infant-illnesses/influenza.html. If you think your baby has symptoms of the flu, contact your child’s healthcare provider.
If a male has the flu, could it affect fertility (ability to get partner pregnant) or increase the chance of birth defects?
Illnesses that cause fever, such as the flu, might cause a temporary reduction in the movement or number of sperm which could make it harder to get a partner pregnant during that time. Close contact may not be recommended when you have the flu to try to avoid passing the flu to your partner. In general, however, exposures that fathers or sperm donors have are unlikely to increase the risk to a pregnancy. For more information, please see the fact sheet 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.