Researchers led by a Michigan State University professor will conduct two studies of whether infection with the COVID-19 virus or vaccination to prevent COVID-19 is affecting the menstrual cycles of women and girls. The studies, funded by the National Institutes of Health, follow anecdotal reports by some women that they had heavier or irregular menstrual cycles after they were infected with the virus or inoculated against it.

“We want to tease out whether being infected is having any effect on menstruation,” said Stacey Missmer, ScD, a College of Human Medicine professor of Obstetrics, Gynecology and Reproductive Biology, who will lead the two studies. The studies also will examine whether “being vaccinated is having either a beneficial or detrimental effect on menstruation,” she said. 

The research will expand on two long-running studies of infertility and endometriosis already underway, one following more than 40,000 adult women, the other focusing on 1,500 adolescent girls. “We think there might be more of an impression of menstrual change among the adolescents and younger women,” Missmer said, “partly because their hormones and reproductive systems are still in maturation.”