As more people become eligible for COVID-19 vaccines, more questions and misconceptions about the health risks arise, especially related to pregnancy, fertility and breastfeeding.

“It is normal, and appropriate, to ask questions about medical treatments, including vaccines,” says Johanna Warren, M.D., interim director of the OHSU Center for Women’s Health. “However, it is important that people seek credible resources to help them make the most informed decision possible.”

The OHSU Center for Women’s health responds to common questions about COVID-19 vaccines and women’s health. 

With an abundance of ever-changing information about COVID-19 on the internet, it can be hard to figure out what is accurate.

Warren, an associate professor of family medicine and obstetrics and gynecology in the OHSU School of Medicine, answers some of the most commonly asked questions about the COVID-19 vaccine and women’s health:
 

1. Is it safe for people who are pregnant or breastfeeding to get a COVID-19 vaccine?
   
   Yes. Similar to influenza or TDaP vaccines, the currently available COVID-19 vaccines don’t contain live bacteria or virus. There are no data to indicate they are unsafe during pregnancy or breastfeeding.
   
   The American College of Obstetrics and Gynecologists recommends that vaccines should not be withheld from those who are pregnant or lactating. Data do suggest that these people may be at higher risk of severe illness with COVID-19 infection.
   
   Pregnant or lactating people considering vaccination should talk with their clinical care team to help make a decision.
    

2. Can a child of a vaccinated mother benefit from antibodies?
   
   Yes. COVID-19-vaccinated mothers who breastfeed can pass virus protection on to their babies. A study recently published in the Journal of the American Medical Association found that a COVID-19 vaccination stimulates antibodies in breast milk for up to six weeks after vaccination. This may help a baby’s immune system prevent serious illness until a COVID-19 vaccine is approved for broad pediatric use.
   
    
3. Is it more common for women to have side effects from the vaccine?
   
   Yes. Researchers at the Centers for Disease Control and Prevention recently reviewed safety data from more than 13 million Americans who received Pfizer and Moderna COVID-19 vaccine doses, and more than 79% of reported side effects came from individuals who identify as women.
   
   “These data are consistent with previous reports of side effects from non-COVID-19 vaccines, such as influenza, and indicate that different sexes may indeed have different responses when it comes to vaccine,” says Warren. “What the data don’t necessarily tell us, is why.”
   
   In some cases, Warren notes, it may be behavioral. “Women are often more likely to report side effects of a vaccine than men, even if their symptoms are exactly the same,” she says. “In other cases, genetic differences between males and females may be to blame.”
   
    
4. Are people required to take a pregnancy test before they receive a COVID-19 vaccine?
   
   No. The Centers for Disease Control and Prevention does not recommend, or require, pregnancy testing before COVID-19 vaccination.
   
    
5. Will the COVID-19 vaccine cause infertility?
   
   No. People trying to get pregnant now, or who may want to get pregnant in the future, can receive a COVID-19 vaccine as soon as they are able.
   
   Currently, there is no evidence to suggest that any vaccines, including COVID-19 vaccines, cause fertility problems.
   
    
6. Will the COVID-19 vaccine alter DNA?
   
   No. COVID-19 vaccines do not change or interact with DNA in any way.
   
   Currently, two types of COVID-19 vaccines have been authorized for use in the United States: messenger RNA (mRNA) vaccines such as Pfizer and Moderna, and the Johnson & Johnson viral vector vaccine.
   
   According to the Centers for Disease Control and Prevention, both mRNA and viral vector COVID-19 vaccines deliver instructions – or genetic material – to our cells to start building protection against the virus that causes COVID-19. However, the material never enters the nucleus of the cell, which stores our DNA. This means the genetic material in the vaccines cannot affect or interact with our DNA in any way.
   
   All COVID-19 vaccines work with the body’s natural defenses to safely develop immunity to disease.
    
7. Will the COVID-19 vaccine alter the results of a mammogram?
   
   Maybe. However, that doesn’t mean that people should avoid either.
   
   For some people, getting a COVID-19 vaccine causes swelling in lymph nodes under the arm in which they got the shot. The swelling is a normal sign that the body is building protection against COVID-19. However, it could also cause a false alarm on a mammogram.
   
   The OHSU Center for Women’s Health recommends that people due for a routine screening mammogram consider getting the mammogram before getting the vaccine, or wait at least four weeks after their Johnson & Johnson vaccine, or second dose of the Pfizer or Moderna vaccine. 
   
   People should not delay getting a mammogram if they have a new breast lump, breast pain or other new breast concern.
   
    
8. Should pain medication be taken before obtaining a vaccine dose?
   
   No, in most cases.
   
   Pain relievers like acetaminophen or ibuprofen may reduce the body’s immune response to a vaccine. Health care professionals recommend against pre-medicating to lessen vaccine side effects.
   
   There are a few exceptions, according to Warren. “If a person uses at-home pain medication for a serious illness or injury, or as a part of a daily routine as directed by their health care provider, neither the vaccine nor the pain management process should be delayed or ignored,” she says.
   
   As needed, pain medications may be used to treat side effects after getting the vaccine.
   
    
9. Was fetal tissue used to make the COVID-19 vaccine?
   
   No. Available COVID-19 vaccines do not contain aborted fetal tissue.  
   
   However, all three vaccines that received emergency use authorization from the U.S. Food and Drug Administration did use fetal cell lines. Fetal cells lines are not the same as fetal tissue. They are cells that grow in a laboratory and do not contain tissue from a fetus.
   
   Pfizer and Moderna used fetal cell lines to test their vaccines, while Johnson & Johnson uses fetal cell lines in vaccine development, confirmation and production. 
   
    
10. Does the COVID-19 vaccine cause heavier or irregular periods?
    
    It is too soon to tell.
    
    A growing number of people worldwide have reported changes to their menstrual cycles, including irregularity, after receiving a COVID-19 vaccine. Currently, there is no scientific evidence to confirm that changes to menstrual cycles are directly related to approved COVID-19 vaccines.
    
    Other factors can cause menstrual cycle changes, including increased stress or medications like birth control pills or IUDs. Warren suggests that anyone experiencing unusual heavy bleeding or pain should talk to their primary care provider whether or not they got the vaccine.
    
    “These symptoms could also be signs of pregnancy, menopause or significant underlying medical condition,” said Warren. “Individuals should never dismiss any noticeable health changes, even beyond their monthly cycle. Always check in with a trusted health care provider.”

Overall, says Warren, “COVID-19 vaccines currently available are safe and effective against preventing severe illness, or death, from the virus. While potential side effects may occur for some, they often resolve quickly and offer significantly less health risk than does contracting COVID-19.”