Influence of COVID-19 pandemic and vaccination on the menstrual cycle: A retrospective study in Hungary

Abstract

Observations of women and clinicians indicated that the prevalence of menstrual cycle problems has escalated during the COVID-19 pandemic. However, it was not clear whether the observed menstrual cycle changes were related to vaccination, the disease itself or the COVID-19 pandemic-induced psychological alterations. To systematically analyze this question, we conducted a human online survey in women aged between 18 and 65 in Hungary. The menstrual cycle of 1563 individuals were analyzed in our study in relation to the COVID-19 vaccination, the COVID-19 infection, the pandemic itself and the mental health. We found no association between the COVID-19 vaccination, the vaccine types or the COVID-19 infection and the menstrual cycle changes. We also evaluated the menstrual cycle alterations focusing on three parameters of the menstrual cycle including the cycle length, the menses length and the cycle regularity in three pandemic phases: the pre-peak, the peak and the post-peak period in Hungary. Our finding was that the length of the menstrual cycle did not change in any of the periods. However, the menses length increased, while the regularity of the menstrual cycle decreased significantly during the peak of the COVID-19 pandemic when comparing to the pre- and post-peak periods. In addition, we exhibited that the length and the regularity of the menstrual cycle both correlated with the severity of depression during the post-peak period, therefore we concluded that the reported menstrual cycle abnormalities during the peak of COVID-19 in Hungary might be the result of elevated depressive symptoms.

Keywords: COVID-19 pandemic; COVID-19 vaccines; SARS-Cov-2 infection; depression; human surveys; menstrual cycle.

Figure 1

Pie charts show the percentage of different age groups (A), different places of residence (B) and different educational background (C) of the female participants.

Figure 2

Pie charts demonstrate the percentage of vaccinated and unvaccinated individuals (A) and the proportion of the types of vaccines received in the vaccinated group (B). The percentage of participants with and without menstrual cycle problems after vaccination is also shown (C). It is also indicated how many doses of vaccine were given to those with menstrual cycle problems (D). In addition, pie charts show how the proportion of individuals with menstrual problems and without menstrual problems varied for mRNA-based (Pfizer-BioNTech, Moderna), adenovirus-based (AstraZeneca, Sputnik, Janssen) and conventional vaccines (Sinopharm) (E).

Figure 3

Pie charts show the percentage of participants who were or were not infected with SARS-CoV-2 (A), detailing the proportion of infected individuals based on the severity of the infection (B). The percentage of participants with and without menstrual cycle problems after SARS-CoV-2 infection (C) or no infection (D) is also demonstrated.

Figure 4

(A) Histograms show the percentage of female individuals bleeding more frequently than 24 days, between 24 and 38 days, less frequently than 38 days and having no regular menstrual bleeding during the pre-peak, the peak, and the post-peak period. (B) Histograms illustrate the percentage of female participants with menses length lasting for 1-2 days, 3-7 days, more than 7 days or having no regular bleeding during the pre-peak, the peak, and the post-peak period. (C) Histograms demonstrate the percentage of female respondents with unpredictable cycle, having regular cycle with a maximum delay of 1-2 days, usually regular cycle with 1-2 missed cycles or 1-2 weeks difference a year, or not regular menstrual cycle during the pre-peak, the peak, and the post-peak period. ***p≤0.001.

Figure 5

Histograms depict the menses length (A) and the regularity of the menstrual cycle (B) in relation to the severity of depression determined by the BDI.