Experts say there is no indication that vaccines affect fertility. Most people’s periods go back to normal within one cycle.
By Knvul Sheikh
Some people experience headaches or sore arms after getting vaccinated. Others may have nausea or swollen lymph nodes. Now, a growing body of research is pointing to yet another potential side effect of Covid-19 vaccines: changes in menstrual cycles.
In a study published on Tuesday in BMJ Medicine, researchers reported that, on average, vaccinated people experienced about a one-day delay in their periods compared with those who did not get vaccinated. But like other side effects of vaccines, this change was temporary. One cycle after vaccination, people’s periods tended to return to normal.
The research expands on the team’s earlier findings as well as anecdotal reports from people who noticed erratic periods after receiving their shots. It includes data from nearly 20,000 people around the world — 14,936 of whom were vaccinated and 4,686 who were not.
“Menstruation is woefully understudied, which is troubling considering it is a key indicator of fertility and overall health,” said Dr. Alison Edelman, a professor of obstetrics and gynecology at Oregon Health & Science University School of Medicine and the paper’s lead author. “We hope our findings further validate what so many individuals reported experiencing, and allow health care professionals to provide patients with better care and clinical recommendations.”