COVID-19 Infection May Have Short-Term Impact on Male Fertility


But vaccines do not cause infertility or harm pregnancy chances, Boston University School of Public Health research results show.

Getting a COVID-19 vaccine does not affect the chances of becoming pregnant, but skipping the vaccination and contracting the virus could reduce male fertility, according to the results of a new study from Boston University (BU) School of Public Health (SPH).

In the study of couples trying to conceive, results, which were published in the American Journal of Epidemiology, show no association between COVID-19 vaccination and the likelihood of conception in female or male partners who received the Johnson & Johnson, Moderna, or Pfizer-BioNTech vaccines.

“Our study shows, for the first time, that COVID-19 vaccination in either partner is unrelated to fertility among couples trying to conceive through intercourse,” Amelia Wesselink, a research assistant professor of epidemiology at BU SPH) said in a statement. “Time-to-pregnancy was very similar, regardless of vaccination status.”

Investigators analyzed survey data on COVID-19 vaccinations, infection, and fecundability, the probability of conception per the menstrual cycle, among female and male individuals in the SPH-based Pregnancy Study Online (PRESTO).

PRESTO is an ongoing study funded by the National Institutes of Health that enrolls women trying to conceive.

The study follows individuals from preconception through 6 months after delivery. There are about 2126 individuals included in Canada and the United States who provided information on characteristics of their partners and lifestyle, medical, and sociodemographic, factors between December 2020 and September 2021. The individuals were followed through November 2021.

The fertility rates among female individuals who received at least 1 dose of a vaccine were nearly identical to unvaccinated female individuals. They were also similar to male partners who had received at least 1 dose of a COVID-19 vaccine compared with unvaccinated male individuals.

Additional analyses considered brand of vaccine and number of doses, geographic region, infertility history, and occupation. These considerations did not indicate any adverse effect of vaccination on fertility.

Although COVID-19 infection was not strongly associated with fertility, men who tested positive within 60 days of a given cycle had reduced fertility compared with those who never tested positive or tested positive at least 60 days prior.

This supports previous research results linking COVID-19 with poor sperm quality and other reproductive dysfunction.

“These findings provide reassuring evidence that COVID vaccination in either partner does not affect fertility among couples trying to conceive,” Lauren Wise, ScD, an SPH professor of epidemiology, said in the statement, adding that the results are robust, because PRESTO includes individuals at various stages, including before and after pregnancy.

A large study size and geographic diversity were also strengths, “as was our control for many variables, such as age, socioeconomic status, preexisting health conditions, occupation, and stress levels,” she said.

Investigators also looked at PRESTO data for evidence that COVID-19 vaccines affect menstruation, as some women have reported changes to their periods after receiving a shot.

The latest fertility findings should help relieve concerns about short-term changes to the menstrual cycle affecting the ability to conceive, Wise said.

The investigators hope to publish the results from the menstruation study in spring 2022.


COVID-19 vaccines don’t cause infertility or harm pregnancy chances, Boston University research shows. EurekAlert. News release. January 24, 2022. Accessed January 28, 2022.

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