COVID-19 vaccination possibly linked to menstrual abnormalities

A high incidence of menstrual disorders among women aged ≤54 years has been noted following COVID-19 vaccination, reveals a Netherlands study. Analysis of spontaneous reports supports this observation.

A total of 24,000 spontaneous reports of menstrual abnormalities and more than 500 episodes of menstrual abnormalities among 16,929 women included in the cohort event monitoring (CEM) study were analysed. The CEM study reported an incidence of 41.4 per 1,000 women aged ≤54 years.

The most common menstrual abnormalities were amenorrhoea/oligomenorrhoea and heavy menstrual bleeding, which accounted for nearly half of the disorders reported.

Notably, significant associations were seen for women aged 25‒34 years (odds ratio [OR], 2.18, 95 percent confidence interval [CI], 1.45‒3.41) and for the Pfizer vaccine (OR, 3.04, 95 percent CI, 2.36‒3.93). However, no association was found for body mass index and presence of comorbidities assessed.

“This [finding] suggests that a relation between COVID-19 vaccination and menstrual abnormalities is plausible and should be further investigated,” the authors said.

For this study, the authors summarized all reports of menstrual abnormalities received by the Netherlands Pharmacovigilance Centre Lareb in the spontaneous reporting system between February 2021 and April 2022.

The authors conducted logistic regression analysis on the reported menstrual abnormalities in the CEM study to examine the relationship between person characteristics, prior SARS-CoV-2 infection, and use of hormonal contraceptives and the occurrence of menstrual abnormalities after vaccination.