Data reassuring on menstrual changes after Covid-19 vaccine, researchers find

Any menstrual changes after Covid-19 vaccination are short-lived and small compared with natural variation in normal cycles, according to an assessment of the latest evidence published by the British Medical Journal (BMJ). Many women have reported changes to their periods after vaccination. Two new observational studies on the issue provide reassuring data, said Dr Victoria Male, a reproductive specialist at Imperial College London. The first study drew on data from 3,959 Americans who logged at least six consecutive cycles on a tracking app. Of these, 2,403 were vaccinated while the remainder acted as a control group.