Descriptive analysis of menstrual alterations reported to the Spanish pharmacovigilance system (SEFV as acronym of its name in Spanish) after vaccination against COVID-19

ABSTRACT

Objective: • To describe the most reported menstrual alterations to the SEFV in relation to vaccination against COVID-19. • To stratify cases by age, type of vaccine and reporter. • To collect the latencies of adverse events. Material and/or methods: Review of the notifications uploaded to the FEDRA database with the following search criteria the suspected drug is a vaccine against COVID-19, the adverse drug reaction (ADR) is part of the Meddra HLGT “alterations of menstrual flow” and the upload date is between the date of authorisation of the first vaccine (22/12/20) and the cut-off date established by protocol (3/11/2021). Also, those cases corresponding to Canary Islands have been selected for a detailed analysis. Results: There are 2275 notifications in Spain that meet the search criteria. The SEFV is the source of 98% of the notifications, being the pharmaceutical industry the source of the 2% left. In Canary Islands, there have been 80 notifications that meet the criteria. Of these, 87.5% come from female users (patients). The average age is 36 years. The most reported menstrual disorders were “intermenstrual bleeding,” “menstrual disorder” and “irregular menstruation.” The latencies described have a mean of 12.5 days with a median of 6 days and a mode of 3 days, appearing after the first dose in most cases. Conclusions: Most of the reports are from female users. Coding is complex due to the difficulty of the terms, which complicates data analysis. Reported reactions are diverse, being the most frequent terms non-specific. Menstrual disturbances interfere with daily life, are underreported and under-diagnosed.