• By Deb Balzer

What pregnant and breastfeeding women should know about COVID-19 vaccine

January 21, 2021

Pregnant women are at an increased risk for serious illness from COVID-19. "Compared to nonpregnant women who have the same health and age, a COVID-infected woman is about 1.3 to 1.4 times more likely to end up in the hospital when she's pregnant," says Dr. Regan Theiler, a Mayo Clinic obstetrician.

Should pregnant and breastfeeding women be vaccinated for COVID-19? While there are limited data about current COVID-19 vaccines in pregnant and breastfeeding patients, there are many questions. A Centers for Disease Control and Prevention report states no unexpected pregnancy or infant outcomes have been observed related to COVID-19 vaccination during pregnancy and safety monitoring in pregnant women continues.

In this Q&A, Dr. Theiler answers questions about COVID-19 vaccines for pregnant and breastfeeding women, and women who plan on becoming pregnant:

Watch: Dr. Regan Theiler discusses the COVID-19 vaccine for pregnant women.

Journalists: Broadcast-quality sound bites are available in the downloads at the bottom of the post. Please "Courtesy: Regan Theiler, M.D., Ph.D./OB-GYN/Mayo Clinic."

Should pregnant women be vaccinated for COVID-19?
Since the emergency use authorization was granted, The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine have been firm in recommending that pregnant women have access to COVID-19 vaccines. That is, if women so choose, they should be able to be vaccinated for COVID-19.

Can a fetus get COVID-19 if the mother is vaccinated for COVID-19?Through vaccination for COVID-19, the baby should not be exposed to the virus. It is known that the COVID-19 vaccines are the genetic code for a single protein. It doesn't replicate in a person. It doesn't cause an infection with COVID-19. There's no virus floating around in a woman. Any vaccine that has a live virus that's replicating is not used in pregnant women because of any theoretical risk. It is thought that there is no risk that this would cause an infection in a pregnant woman and cause an infection that goes to the baby.

Are COVID-19 vaccines safe for pregnant women?
Because this is an emergency use authorization, and because any medication or vaccine during its first iteration of trials is never tested in pregnant women, there is no direct evidence of safety in pregnancy. What is known is that there is a lack of theoretical evidence of harm. 

There is no conceivable reason why COVID-19 vaccines should be harmful to pregnant women. None of the components of the vaccines ― the nanoparticles ― are known to be harmful in pregnancy. The best evidence for pregnant women suggests that being vaccinated for COVID-19 is a lot safer than getting COVID-19.

Are COVID-19 vaccines safe for women who are breastfeeding?
There is no indication that COVID-19 vaccines are harmful or damaging to women who are breastfeeding or their infants.

Do COVID-19 vaccines cause infertility?
There's no evidence of COVID-19 vaccines causing infertility. 

There's been a sophisticated anti-vaccine campaign that originated online. The New York Times had a great article about it, going through the levels of disinformation and where it came from. 

It sounds scientific, and it goes something like this. There's a protein in the placenta that has similarities to viruses. And if you have antibodies to viruses that are induced by this vaccine, it will cause you to have a miscarriage and the pregnancy did not implant in your uterus. This is completely made up. It sounds smart. It's based in molecular biology. It's written by a scientist. But it's fundamentally not true. 

If that were true, then women who had COVID-19 ― millions of women now ― would be more likely to have miscarriages and not get pregnant. That's because they would have those same antibodies because it's the identical gene producing the identical kinds of antibodies in the virus infection and in the COVID-19 vaccines. 

OK, so you have the same antibodies; yet, in women who have had COVID-19, there have been other viral infections with even more homology to this protein. No signals are being seen for increased miscarriages or decreased fertility. 

Again, this is a sophisticated scientific-sounding campaign that was purposefully put out on the internet to prevent women especially from getting this vaccine. It's not based in truth, and it's doing significant harm.

Do you have recommendations for women who are pregnant or breastfeeding, or are planning a pregnancy, to avoid getting infected with COVID-19?
Everyone should continue social distancing. Everyone should continue masking. All of those safety measures apply to pregnant women, lactating women and women who are contemplating a pregnancy. 

There are no formal recommendations yet. Knowing how good these COVID-19 vaccines are at preventing infection and how dangerous the infection is in pregnancy, the recommendation is that women stay on their contraception, go through the COVID-19 vaccination series, and then contemplate conception. COVID-19 vaccines are known to be effective.

Mayo Clinic follows the guidelines of the American College of Obstetricians and Gynecologists and Society for Maternal-Fetal Medicine, as well as independent data. 


For the safety of our patients, staff and visitors, Mayo Clinic has strict masking policies in place. Anyone shown without a mask was either recorded prior to COVID-19 or recorded in a non-patient care area where social distancing and other safety protocols were followed.

Information in this post was accurate at the time of its posting. Due to the fluid nature of the COVID-19 pandemic, scientific understanding, along with guidelines and recommendations, may have changed since the original publication date

For more information and all your COVID-19 coverage, go to the Mayo Clinic News Network and mayoclinic.org.

Learn more about: Tracking COVID-19 and COVID-19 trends

Jan. 20, 2021- Mayo Clinic COVID-19 trending map using red color tones for hot spots
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