Impact of coronavirus disease 2019 vaccination on live birth rates after in vitro fertilization

Abstract

ObjectiveTo investigate COVID-19 vaccination on live birth rates in patients undergoing in vitro fertilization. DesignRetrospective cohort study SubjectsPatients who underwent fresh or frozen embryo transfer (FET) cycles at an academic center between January 1, 2020 and December 31, 2021. ExposureCOVID-19 vaccination, defined as completing a two-dose regimen (Pfizer or Moderna) or one dose regimen (Johnson & Johnson/Janssen) prior to cycle initiation. Main Outcome MeasuresThe primary outcome was live birth rate per embryo transfer. Secondary outcomes included positive hCG and clinical pregnancy rates per embryo transfer. Outcomes from cycles among vaccinated and unvaccinated patients were compared. Descriptive statistics were used to analyze demographic and cycle characteristics with Student’s t, Wilcoxon rank sum, Pearson Chi-square, and Fisher’s exact tests as appropriate for univariable analysis. Generalized estimating equation models were used to examine the strength of the relationship between vaccination status and pregnancy outcomes. ResultsAmong 709 unvaccinated and 648 vaccinated fresh cycles, there were no statistically significant differences between the number of oocytes retrieved, oocyte maturity, fertilization, and blastocyst utilization rates. In adjusted multivariable analysis, there was no statistically significant difference between fresh cycles among vaccinated patients compared to unvaccinated patients with rates of positive hCG (aOR 1.37, 95% CI 0.84-2.25), clinical pregnancy (aOR 1.22, 95% CI 0.73-2.03), or live birth (aOR 1.37, 95% CI 0.79-2.25) per embryo transfer. Among 264 unvaccinated and 423 vaccinated FET cycles, vaccinated patients had higher odds of positive hCG (aOR 1.54, 95% CI 1.08-2.20), clinical pregnancy (aOR 1.80, 95% CI 1.27-2.56), and live birth (aOR 2.31, 95% CI 1.60-3.32) per embryo transfer compared to unvaccinated patients. ConclusionPatients who were COVID-19 vaccinated prior to FET had higher rates of biochemical pregnancy, clinical pregnancy, and live birth. Vaccination was not associated with pregnancy or live birth rates after fresh cycles. This study contributes to evidence supporting COVID-19 vaccination for patients attempting pregnancy.