Covid-19 Vaccination and Assisted Reproduction Outcomes: A Literature Review and Meta-Analysis

ABSTRACT

Objective: The COVID-19 pandemic remains a significant global health risk and poses an increased danger to pregnant mothers. There remains significant vaccination hesitancy amongst many in the population, in part due to unfounded claims regarding its effect on fertility (1). We conducted a literature review and meta-analysis comparing the available data on effects of COVID-19 vaccination on both ovarian stimulation and embryo transfer outcomes. Material(s) and Method(s) A literature search of PubMed was conducted using the search terms COVID-19, SarsCov2, vaccines, bnt162 vaccines, 2019-ncov vaccine mrna-1273, in vitro fertilization, egg retrieval, oocyte retrieval and embryo transfer. Reported ovarian stimulation outcomes included number of oocytes retrieved, number of mature oocytes, number of fertilized oocytes, and number of blastocysts formed, and were compared using Student's t-test. Embryo transfer outcomes included implantation rate, clinical pregnancy rate, and ongoing pregnancy rate, and were compared using chi square. Meta-analysis was performed by Standard Mean Difference method for oocyte outcomes and the Cochran-Mantel-Haenszel method for embryo transfer outcomes. Result(s) Our search retrieved 12 studies conducted between August 2021 and March 2022. Of them, only 6 compared outcomes between COVID-19 vaccinated and unvaccinated patients. Two included only ovarian stimulation outcomes, two included only embryo transfer outcomes, and two studies included outcomes for both. Of the ovarian stimulation outcomes reported, data adequate for meta-analyses were only included for the number of oocytes retrieved and number of mature oocytes. There were no statistically significant differences reported between vaccinated and unvaccinated patients amongst the pooled data from the four studies for the ovarian stimulation parameter - number of oocytes retrieved (mean 10.6 vs 10.6, 95% CI -0.144 - 0.157), or the number of MII oocytes (mean 7.43 vs 7.95, 95% CI -0.055 - 0.247). There were similarly no statistically significant differences amongst the pooled data from the four studies for any of the embryo transfer parameters - implantation rate (OR 0.97, 95% CI 0.76 - 1.24), clinical pregnancy rate (OR 0.88, 95% CI 0.70 - 1.11), or ongoing pregnancy rate (OR 1.22, 95% CI 0.78 - 1.91). Conclusion(s) The current literature demonstrates no differences in either ovarian stimulation or embryo transfer outcomes following COVID-19 vaccination. There remain several key parameters, however, that would benefit from additional investigation. Impact Statement Patients can be reassured the current evidence reaffirms the safety profile of the mRNA COVID-19 vaccine and does not affect fertility. References 1. Hsu AL, Johnson T, Phillips L, Nelson TB. Sources of Vaccine Hesitancy Pregnancy, Infertility, Minority Concerns, and General Skepticism. Open forum infectious diseases 2022;9ofab433-ofab. Copyright © 2022