Impact of vaccination against COVID-19 on the outcomes of in vitro fertilization–embryo transfer: a retrospective cohort study

BACKGROUND: Vaccination against coronavirus disease 2019 (COVID-19) has become the primary approach in the fight against the spread of COVID-19. Studies have shown that vaccination against COVID-19 has adverse effects, particularly on human reproductive health, despite the fact that vaccination rates are still on the rise. However, few studies have reported whether vaccination affects the outcome of in vitro fertilization–embryo transfer (IVF–ET) or not. In this study, we compared the outcome of IVF–ET and the development of follicles and embryos between vaccinated and unvaccinated groups. METHODS: A single-center retrospective cohort study of 10,541 in vitro fertilization (IVF) cycles was conducted from June 2020 to August 2021. 835 IVF cycles with a history of vaccination against COVID-19 and 1670 IVF cycles that served as negative controls were selected and analyzed utilizing the Matchlt package of R software (http://www.R-project.org/) and the nearest neighbor matching algorithm for propensity-matched analysis at a 1:2 ratio. RESULTS: The number of oocytes collected in the vaccinated group and the unvaccinated group were 8.00 (0, 40.00) and 9.00 (0, 77.00) (P = 0.073) and the good-quality embryo rates of the two groups were 0.56±0.32 and 0.56±0.31 averagely (P = 0.964). Clinical pregnancy rates for the vaccinated group and unvaccinated group were 42.4% (155/366) and 40.2% (328/816) (P = 0.486) and biochemical pregnancy rates were 7.1% (26/366) and 8.7% (71/816) (P = 0.355). Two other factors were analyzed in this study; vaccination among different genders and different types (inactivated vaccine or recombinant adenovirus vaccine) showed no statistically significant effect on the above outcomes. CONCLUSIONS: In our findings, vaccination against COVID-19 showed no statistically significant effect on the outcomes of IVF-ET and the development of follicles and embryos, nor did the gender of the vaccinated person or the formulation of vaccines show significant effects.