Couples who get a covid vaccine do not reduce their chances of conceiving a child, but men who get infected with Covid do reduce their odds slightly, the National Institutes of Health (NIH) said Thursday.

A study that looked at 2,000 couples found no difference in their chances of having a baby if either partner was vaccinated compared to unvaccinated couples. However, if the male partner had been infected Covid within 60 days before a menstrual cycle there was a slightly lower chance of conception, according to the NIH-funded study in the American Journal of Epidemiology.

“The findings provide reassurance that vaccination for couples seeking pregnancy does not appear to impair fertility,” said Diana Bianchi, M.D., director of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development, which funded the study. “They also provide information for physicians who counsel patients hoping to conceive.”

Type of covid vaccine didn’t matter

Researchers said their findings were consistent regardless of whether the couple had received one or two doses of the vaccine, the type of vaccine they received, or how recently they were vaccinated.

Having tested positive for SARS-CoV-2 was not, overall, associated with reduced odds of conception, NIH said, but if the male partner tested positive within two months of a menstrual cycle, his partner was 18 percent less likely to conceive during that cycle. Testing positive longer than 60 days previous had no impact.

It is possible that the fever that often accompanies Covid could impact the male’s fertility, as would inflammation of the testes and nearby tissues or erectile dysfunction, all common after a Covid infection.

While previous studies have shown that Covid vaccines do no harm to pregnant mothers and in fact provide some protective support for the baby, the researchers in this study pointed out that vaccination of the male partner could eliminate the short-term decline in the odds of a couple conceiving.