The effect of COVID-19 vaccinations on menstrual cycle and serum anti-Mullerian hormone levels in reproductive age women

The aim of this prospective cohort study was to investigate the effect of coronavirus disease 2019 (COVID-19) vaccinations on menstrual cycle and ovarian reserve in reproductive aged-women. Health care providers (n = 258) vaccinated with inactivated (CoronaVac) and mRNA based (Pfizer-BioNTech®) COVID-19 vaccines were included. All subjects completed a gynaecological and menstrual history questionnaire and Anti-Mullerian Hormone (AMH) levels were measured in serum samples collected before first vaccination and at 1^st, 3^rd, 6^th and 9^th months. The prevalence of new-onset menstrual dysregulation following vaccination was 20.6% and it was statistically significant compared to baseline (p = 0.001). Menstrual pattern turned back to normal in 59.6% of vaccinated women. Serum AMH levels gradually decreased until 6^th month of follow-up compared to baseline (p < 0.001). A significant increase in serum AMH level was observed at 9^th month of follow-up compared to 6^th month follow-up levels (p < 0.001). The decrease in serum AMH level was statistically significant regardless of serum anti SARS-CoV-2 antibody levels, subgroups of age, occupation, menstrual dysregulation following vaccination and presence of gynaecological diseases. In conclusion, vaccination against SARS-CoV-2 causes a transient decrease on serum AMH levels and moderate irregularities in menstrual pattern increasing with age and is mostly reversible.