The European Medicines Agency's safety committee said on Friday it was reviewing reports of heavy menstrual bleeding and absence of menstruation after COVID-19 vaccines from Pfizer/BioNTech and Moderna.
The assessment was in view of reports of menstrual disorders after receiving both vaccines, and it was not yet clear whether there was a causal link between the COVID-19 vaccines and the reports, the agency said.
The EMA in December also said it had not established a link between changes in menstrual cycles and COVID-19 vaccines, after a study in Norway suggested some women had heavier periods after being inoculated.
The agency on Friday added that there was also no evidence to suggest that COVID-19 vaccines affected fertility.
After reviewing the available evidence, the EMA's Pharmacovigilance Risk Assessment Committee (PRAC) said it decided to request an evaluation of all available data, including reports from patients and healthcare professionals, clinical trials and the published literature.