Even though they’ve been debunked, potential fertility issues have been a top concern among many people who are hesitant to get the COVID-19 vaccine. Now, a new study only adds to the evidence that getting pregnant is not an issue in people who have gotten the shot.
The study, which was funded by the National Institutes of Health (NIH) and published in the American Journal of Epidemiology, analyzed data from 2,126 women between the ages of 21 and 45 that was collected from December 2020 to September 2021. The women were asked to complete a questionnaire on a slew of things, including their income, lifestyle, reproductive and medical histories, whether they had been vaccinated against COVID-19 and whether they or their partners had ever tested positive for SARS-CoV-2, the virus that causes COVID-19. The women completed follow-up questionnaires every eight weeks until they became pregnant or up to 12 months if they didn’t become pregnant.
After analyzing the data, the researchers found that there were no major differences in rates of conception per menstrual cycle between women who were unvaccinated and those who were in a relationship where at least one partner received at least one dose of the COVID-19 vaccine. That also held true when the data was broken down by whether the study participants and their partners had one or two doses of the vaccine, the type of vaccine they received, and how recently they were vaccinated.
The researchers also found that having a history of a COVID-19 infection wasn’t linked to issues conceiving — with a small exception. Couples where the male partner tested positive for the virus within 60 days of a given cycle were 18 percent less likely to conceive during that cycle than their counterparts who hadn’t been infected. However, that difference went away after 60 days had passed.
“These findings indicate that male SARS-CoV-2 infection may be associated with a short-term decline in fertility and that COVID-19 vaccination does not impair fertility in either partner,” the researchers concluded.
This isn’t the only study to conclude that the COVID-19 vaccines have no impact on fertility or pregnancy outcomes. A scientific review published in the journal Human Reproduction in December concluded that men and women “have no fertility problems or increased adverse pregnancy outcomes after vaccination.” It also found that “the benefits of maternal antibodies transferred through the placenta outweigh any known or potential risks.”
A study published in September looked at implantation rates in people undergoing IVF and found that there was no difference in success rates in people who had received the COVID-19 vaccine, had previously been infected with COVID-19, or had never been infected with the virus or received the vaccine. (Implantation rate describes the number of embryos that have implanted themselves into the uterine lining compared to the total number of embryos transferred during IVF.) “Reports claiming that COVID-19 vaccines or illness cause female sterility are unfounded,” the researchers concluded.
Additionally, the Centers for Disease Control (CDC) published a report in early January, after analyzing data from more than 40,000 pregnant women. It found that there was no difference in preterm birth or small-for-gestational-age births in women who received the COVID-19 vaccine vs. those who were unvaccinated. But it also found that, as of May 2021, only 16.3 percent of pregnant women had received at least one dose of the COVID-19 vaccine during their pregnancy.
If you’re trying to conceive or know you’ll want to conceive at some point in the future, the latest findings will hopefully help you feel even more OK about getting vaccinated. But where did these fertility concerns come from in the first place, and what do doctors think of the latest findings? Here’s what you need to know. (Related: Why Some People Are Choosing Not to Get the COVID-19 Vaccine)
Why are people worried about fertility with the COVID-19 vaccines?
There’s been a lot of misinformation circulating on social media about this, and much of it boils down to concerns and myths over how the COVID-19 vaccines work.
The mRNA vaccines, which are the Pfizer-BioNTech and Moderna vaccines, use genetic material called messenger RNA (mRNA) to tell your body to produce a spike protein found on the surface of SARS-CoV-2, the CDC explains. This prompts an immune response in your body, and you develop antibodies to the virus. Your body quickly eliminates that protein and the mRNA, but the antibodies stay to help keep future SARS-CoV-2 exposures from making you sick.
There have been myths that the mRNA vaccines alter your DNA — not true, the National Institutes of Health (NIH) says — and claims that the vaccine contains a spike protein called syncytin-1, which is linked with the function of the placenta. In case you need a refresher, the placenta is an organ that develops during pregnancy to help provide oxygen and nutrients to the developing fetus.
“The theory that mRNA vaccines will cause the immune system to attack the placenta is not true,” says psychiatrist and women’s health expert Jennifer Wider, M.D. “Syncytin-1 is not contained in the spike protein and they are not similar.”
FWIW, there does not seem to be the same level of fertility concerns on social media around the Johnson & Johnson COVID-19 vaccine. Unlike the other two vaccines, it uses an inactivated virus to trigger an immune response to COVID-19.
Experts recommend vaccination if you’re trying to conceive or already pregnant.
Major medical organizations, including the CDC, American College of Obstetrics and Gynecologists (ACOG) and Society of Maternal Fetal Medicine (SMFM), recommend the COVID vaccine for women who are considering becoming pregnant, are pregnant, or are breastfeeding.
“The organizations’ recommendations in support of vaccination during pregnancy reflect evidence demonstrating the safe use of the COVID-19 vaccines during pregnancy from tens of thousands of reporting individuals over the last several months, as well as the current low vaccination rates and concerning increase in cases,” ACOG and SMFM announced in a joint statement in July.
“COVID-19 vaccination is recommended for people who are pregnant,” the CDC states on its website. “In addition, everyone who is ages 18 and older, including those who are pregnant, breastfeeding, trying to get pregnant now, or might become pregnant in the future, should get a booster shot.”
COVID-19 can cause serious illness and death in pregnant women. A Nature Medicine study from Scotland published on January 13 found that 98 percent of pregnant patients who were admitted to the ICU for critical care due to COVID-19 between December 2020 and 31 October 2021 in the country were unvaccinated.
As for fertility concerns, the NIH-funded study findings “should lay to rest the misinformation around this issue that has been circulating since even before the vaccines were available,” says infectious disease physician Amesh A. Adalja, M.D., a senior scholar at the Johns Hopkins Center for Health Security. “There is really no biological mechanism for how the vaccines could impact fertility.”
The new study “significantly adds to the growing evidence that vaccines do not negatively impact fertility,” says Dr. Wider.
As such, experts continue to stress the importance of getting the COVID-19 vaccine, if you haven’t already. Says Dr. Adalja: “Getting vaccinated should be the norm for everyone, irrespective of child-bearing status.”
The information in this story is accurate as of press time. As updates about coronavirus COVID-19 continue to evolve, it’s possible that some information and recommendations in this story have changed since initial publication. We encourage you to check in regularly with resources such as the CDC, the WHO, and your local public health department for the most up-to-date data and recommendations.