The assessment is based on reports of menstrual disorders after one or two doses of either Moderna's vaccine Spikevax and Pfizer-Biontech's vaccine Comirnaty.
Disruption of menstruation is very common, and can have a variety of explanations such as stress, fatigue or underlying medical conditions, writes EMA.
There are also reports of menstrual disorders after covid-19 infection.
In Sweden, more than 7,200 women have reported menstrual disorders after covid-19 vaccination.