A Prospective Cohort Study of COVID-19 Vaccination, SARS-CoV-2 Infection, and Fertility

Am J Epidemiol. 2022 Jul 23;191(8):1383-1395. doi: 10.1093/aje/kwac011.


Some reproductive-aged individuals remain unvaccinated against coronavirus disease 2019 (COVID-19) because of concerns about potential adverse effects on fertility. Using data from an internet-based preconception cohort study, we examined the associations of COVID-19 vaccination and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with fertility among couples trying to conceive spontaneously. We enrolled 2,126 self-identified female participants aged 21-45 year residing in the United States or Canada during December 2020-September 2021 and followed them through November 2021. Participants completed questionnaires every 8 weeks on sociodemographics, lifestyle, medical factors, and partner information. We fit proportional probabilities regression models to estimate associations between self-reported COVID-19 vaccination and SARS-CoV-2 infection in both partners with fecundability (i.e., the per-cycle probability of conception), adjusting for potential confounders. COVID-19 vaccination was not appreciably associated with fecundability in either partner (female fecundability ratio (FR) = 1.08, 95% confidence interval (CI): 0.95, 1.23; male FR = 0.95, 95% CI: 0.83, 1.10). Female SARS-CoV-2 infection was not strongly associated with fecundability (FR = 1.07, 95% CI: 0.87, 1.31). Male infection was associated with a transient reduction in fecundability (for infection within 60 days, FR = 0.82, 95% CI: 0.47, 1.45; for infection after 60 days, FR = 1.16, 95% CI: 0.92, 1.47). These findings indicate that male SARS-CoV-2 infection may be associated with a short-term decline in fertility and that COVID-19 vaccination does not impair fertility in either partner.

Keywords: COVID-19; SARS-CoV-2; fecundability; fertility; preconception; prospective cohort; vaccination.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • COVID-19* / epidemiology
  • COVID-19* / prevention & control
  • Cohort Studies
  • Female
  • Fertility
  • Humans
  • Male
  • Prospective Studies
  • SARS-CoV-2
  • United States / epidemiology