Pregnancy and COVID-19 Vaccines: What You Need to Know

Pregnancy and COVID-19 Vaccines: What You Need to Know

Post Date: May 19, 2021

With COVID-19 vaccines now becoming widely available in Montana, women have questions about how the vaccine relates to fertility, pregnancy, and breastfeeding. So, we sat down with Kristi King, RN, FNP, a registered nurse, and family nurse practitioner in Community Health Partners’ Bozeman clinic to get some answers.

Kristi has two young children and is currently breastfeeding one of them. So when she was allowed to receive a vaccine in December 2020, she dug deep into the research done on vaccines, particularly how the vaccines might affect lactating women and their babies. She also knew she would soon be counseling her patients – many of whom are trying to get pregnant, are pregnant, or lactating – about their decisions on whether or not to get vaccinated for COVID-19. In short, she needed to really know her stuff to make the best decision for herself and help patients make their own.

Here’s what she found:


For people who are considering pregnancy in the future, they may be wondering if the COVID-19 vaccines affect fertility. However, there’s no evidence that they do, according to the American College of Obstetricians and Gynecologists (ACOG), and the Society for Maternal-Fetal Medicine (SMFM).

“There’s no reason scientifically that the vaccines would have an effect on a person’s ability to get pregnant,” Kristi said.

While human vaccine trials did not specifically study fertility, no signs of infertility were noted in animal studies. So when it comes to getting a COVID-19 vaccine, future pregnancy shouldn’t be a concern.

In addition, getting vaccinated prior to pregnancy can help protect you against COVID-19 infection, which poses real risks to pregnant women, including breathing difficulties, a higher risk of pre-term birth, and other adverse outcomes.


How about pregnancy? Is there any reason a person shouldn’t get a COVID-19 vaccine while pregnant?

When it comes to big questions about pregnancy, Kristi has always relied on one of the most trusted sources in the industry: the Society of Maternal-Fetal Medicine (SMFM). The organization has regularly updated its Provider Considerations for Engaging in COVID-19 Vaccine Counseling With Pregnant and Lactating Patients to help healthcare providers like Kristi answer these questions.


The SMFM’s latest publication reported that “over 85,000 pregnant people have self-reported after receiving a COVID-19 vaccine within the CDC v-safe program, and the types and frequency of self-reported acute side effects do not appear to differ from those in the general population.” This means that pregnant people are experiencing the same side effects from vaccination as people who are not pregnant. These side effects can include a low-grade fever, chills, and fatigue.

Between December 14, 2020, and February 28, 2021, over 3,900 people who identified as pregnant enrolled in the CDC’s v-safe Vaccine Pregnancy Registry. Since then, 827 completed pregnancies have been registered. Adverse pregnancy outcomes (including spontaneous abortion, stillbirth, pre-term birth, small size for gestational age, congenital anomalies, and neonatal death) all fell within normal ranges. This signifies that the vaccine has no proven effect on completed pregnancy outcomes.


The vaccine is also very effective in pregnant people. According to the National Institute of Child Health and Human Development (NICHD), “current vaccines to prevent COVID-19 are highly effective in producing antibodies in pregnant people, resulting in more antibodies than what is generated from a natural SARS-CoV-2 virus infection. In addition, antibodies produced after vaccination are present in breastmilk and travel across the placenta, indicating that vaccination during pregnancy will also confer immunity to newborns.”

Although the vaccines were made available to pregnant people after they were approved, they did not include pregnant people in the initial trials. These findings from the NICHD indicate that the vaccines promote strong immunity to SARS-CoV-2, like that seen in non-pregnant people.


When it comes to breastfeeding, Kristi says there is no evidence that the COVID-19 vaccines reduce milk production or bring any harmful effects to the baby. She’s found this to be true throughout her own experience, too, having now been vaccinated for more than four months and continuing to breastfeed her 1-year-old son.

“In fact, research shows that you can pass on antibodies to your little ones,” she said.

The Academy of Breastfeeding Medicine released a statement on this topic, explaining further how vaccines work within the body of a new mother.

“While there is little plausible risk for the child, there is a biologically plausible benefit. Antibodies and T-cells stimulated by the vaccine may passively transfer into milk. Following vaccination against other viruses, IgA antibodies are detectable in milk within 5 to 7 days. Antibodies transferred into milk may therefore protect the infant from infection with SARS-CoV-2.”

Kristi is currently participating in the Mount Sinai Icahn School of Medicine Breastmilk Study to better understand how antibodies work in breastmilk. As one of more than 1,500 participants, Kristi regularly pumps additional breastmilk and sends it to researchers to be studied.

Talk to Your Healthcare Provider

Making these kinds of healthcare decisions can be difficult, especially when considering the inception and care of another human life. Kristi highly recommends talking to a healthcare provider who you trust with these kinds of big decisions and who you consider to be an expert in this field.

“In the end,” she says, “you have to have trust in the science behind it.”

Kristi encourages everyone to do their research and look deeper into the sources listed in this blog.

If you have more questions about the COVID-19 vaccines and pregnancy, don’t hesitate to reach out to your nearest CHP clinic. We’ll connect you with the right healthcare provider who can give you the best information to help you make your decision.