Association Between Menstrual Cycle Length and Coronavirus Disease 2019 (COVID-19) Vaccination.
To assess whether
vaccination against coronavirus disease 2019 is associated with changes in
cycle or menstrual length in vaccinated individuals compared to unvaccinated
cohorts. We used the Natural Cycles application to analyze the
positively recorded menstrual cycle data. US citizens aged 18-45 years, 3
consecutive cycles before the first vaccination (cycles 4-6), or a normal cycle
length of 6 cycles (24-38 days) if not vaccinated there is. Period Included
period. Averages within individual variations in cycle and menstrual length
were calculated (3 cycles before vaccination vs. the first and second dosing
cycles of the vaccinated cohort, and the first 3 cycles vs. the non-vaccinated
cohort. Cycles 4 and 5). A mixed-effects model was used to estimate adjusted
differences in cycle and menstrual length changes between vaccinated and
non-vaccinated cohorts. We included 3,959 subjects (2,403
vaccinated; 1,556 unvaccinated). The majority of the vaccinated cohorts
received the PfizerBioNTech vaccine (55%) (Moderna 35%, Johnson & Johnson /
Janssen 7%). Overall, the COVID19 vaccine was associated with a change in cycle
length of less than 1 day in both vaccination cycles compared to the
pre-vaccination cycle (initial dose increased by 0.71 days, 98.75% CI
0.47-0.94). Second dose 0.91, 98.75% CI 0.63-1.19); Unvaccinated subjects
showed no significant changes compared to the three baseline cycles (cycle 4
0.07, 98.75% CI -0.22). ~ 0.35; Cycle 5 0.12, 98.75% CI -0.15 ~ 0, 39). In the
fitted model, the difference in cycle length change between the vaccinated and
non-vaccinated cohorts was less than 1 day at both doses (difference in change:
first dose 0.64 days, 98.75% CI 0.27-1.01; Second dose 0.79 days, 98.75% CI).
0.40-1.18). Changes in menstrual length were not associated with vaccination.
The
menstrual cycle is a clear sign of health and fertility. The characteristics of
menstruation are not static and vary from month to month throughout a person's
life. The International Federation of Gynecology and Obstetrics classifies cycle
length fluctuations of less than 8 days as normal fluctuations. Normal
menstruators can also experience sporadic or stress-related ovulatory
disorders, which can lead to cycle failures or temporary changes in cycle
length. This normal variation may be of concern, especially in connection with new
exposures such as COVID19 vaccination.
Comments
Post a Comment