Since widespread immunization against Covid-19 began last year, doctors and medical researchers have been fielding reports of painful cramps, delayed periods and other changes in menstrual cycles among some who got the vaccines. Now research confirms that the shots can affect menstrual cycles, with one recent study linking vaccination to a slight increase in menstrual-cycle length.
“It’s reassuring that it’s small,” Alison Edelman, a professor of obstetrics and gynecology at Oregon Health & Science University and one of the researchers who conducted the study, said of vaccines’ effect on menstrual cycles. “It’s also validating to individuals who experienced it.”
For the study, published Jan. 5 in the peer-reviewed journal Obstetrics & Gynecology, the researchers tracked six menstrual cycles of about 4,000 study subjects who had received the Pfizer Inc. – BioNTech SE, Moderna Inc. or Johnson & Johnson vaccine or were unvaccinated. It showed that cycles were extended on average by less than a day after one vaccine dose, or up to two days for people who got two doses within a single cycle.
Vaccination wasn’t linked to a change in period length, nor were menstrual changes more common with any particular vaccine.
www.wsj.com/articles/covid-19-vaccines-linked-to-menstrual-cycle-changes-11643902386