COVID vaccines don’t impact male fertility — but getting the virus might, study finds

There’s a possibility unvaccinated adults might avoid getting the COVID-19 vaccine over some concerns expressed on social media about whether it could potentially impact a couple’s ability to have kids.

A new study addresses those concerns and found COVID-19 vaccination doesn’t affect the chances of having a child for either partner, including fertility in those who self-identify as male or female.

However, if a male partner gets infected with COVID-19, the chances of conception might be slightly lower for two months afterward, according to the National Institutes of Health-funded research published Thursday, Jan. 20, in the American Journal of Epidemiology.

Specifically, couples were “18% less likely to conceive” if a male partner tested positive for the virus within 60 days of a woman’s menstrual cycle, the NIH said in a Jan. 20 news release.

The findings suggest a possible connection between male COVID-19 infection and “a short-term decline in fertility,” researchers wrote.

Additionally, they “found no differences in the chances of conception if either male or female partner had been vaccinated, compared to unvaccinated couples,” the NIH said.

The research examined data on 2,126 American and Canadian couples from the Pregnancy Study Online led by Dr. Lauren A. Wise at Boston University. Women were enrolled from December 2020 through September 2021. Then, they were followed up with until November 2021.

Women ages 21 to 45 completed questionnaires every eight weeks, according to the study, about their “sociodemographics, lifestyle, medical factors, and partner information.” Medical-related questions included asking about one’s vaccination status and vaccine brands including Pfizer, Moderna or Johnson & Johnson.

Eligible male partners, 21 and older, were also invited to participate in a related questionnaire.

Couples were asked if they ever tested positive for COVID-19 and if so, when, according to the research.

Of the male participants, 7.8% had tested positive for COVID-19 beforehand compared with 7.2% of the females.

Additionally, most of the women in the study, 73%, received at least one COVID-19 vaccine dose compared with 74% of the men, the study said.

Ultimately, for men, recent COVID-19 infection was linked with a temporary reduction in the chances of their partner getting pregnant within one menstrual cycle, researchers wrote.

“The findings provide reassurance that vaccination for couples seeking pregnancy does not appear to impair fertility,” said Dr. Diana Bianchi, the director of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development.

“They also provide information for physicians who counsel patients hoping to conceive.”

Study authors said speculation that COVID-19 vaccines “may impair female fertility” began with an online blog post.

“Anecdotal reports of menstrual cycle irregularities after vaccination have also contributed to concerns about the vaccine’s potential effect on fertility,” authors wrote.

Prior to this study, NIH-funded research found COVID-19 vaccines are connected to “a small change” in the length of a menstrual cycle and caused slightly longer cycles, McClatchy News reported. However, researchers found it wasn’t “clinically significant,” and the change was temporary.

Researchers in the fertility study said “data on the association between COVID-19 vaccination and fertility are still limited, but do not indicate a harmful association.”