Association between Covishield vaccine and menstrual disturbance. Findings from a cross-sectional study among participants of Zero TB cohort in India.

ABSTRACT

BACKGROUND: The association between covid-19 vaccine and menstrual disturbance is unclear. METHODS: An in-person cross-sectional survey among female members ≥ 18 years enrolled in an ongoing Zero TB prospective cohort in Northern India who had received one or two doses of covid-19 vaccine was conducted to study the characteristics and association of menstrual disturbance within six months of receiving Covishield. RESULTS: Between June 29 and September 5, 2021, 339 females ≥ 18 years of age were administered the survey. Median age was 30 (IQR 22-39) years; 84 % were between 18 and 49 and 16 % were ≥ 50 years old. There were 152 college students, 27 healthcare workers, and 160 nuns. Forty-two women (12 %) had received one dose and 297 (88 %) had received two doses of Covishield. Overall, 66 (20 %) women reported experiencing menstrual disturbance after receiving Covishield vaccine. The problems included early menstruation 6 % (n = 19/339); late menstruation 4 % (n = 14/339); and heavier bleeding 5 % (n = 17/339). Disturbances lasted for less than seven days and cycles normalized in 1-3 months. There was no post-menopausal bleeding. There was no significant difference in menstrual disturbance based on receiving one vs. two doses of Covishield (OR 1.58; 95 % CI 0.55-4.57; p = 0.381). History of SARS-CoV-2 infection was not associated with the development of menstrual disturbance among the vaccinees (OR 0.63; 95 % CI 0.24-1.73; p = 0.379). Presence of emotional disturbance at baseline (OR 31; 95 % CI 3.52-267; p = 0.002) or previous history of dysmenorrhea (OR 41; 95 % CI 8.7-196; p < 0.001) was associated with menstrual disturbance in the vaccinees, indicating their potential to confound or bias study results. CONCLUSION: Menstrual problems were reported by Covishield vaccinees, but they were minor and reversible within three months and do not constitute a ground for vaccine hesitancy. Studies designed to assess causal link taking care to avoid selection bias or confounding are needed.