Fertility outcomes in women undergoing Assisted Reproductive Treatments after COVID-19 vaccination: A prospective cohort study.

Background: Vaccination against Coronavirus-19 disease (COVID-19) was widely administered from 2021 onwards. There is little information on how this vaccine affected fertility after assisted-reproductive-technology (ART). The aim of this study therefore was to determine if COVID-19 vaccination or time-since-vaccination influenced ART outcomes.

Materials and methods: In this prospective cohort study, 502 oocyte-retrieval-cycles and 582 subsequent embryo- transfer-cycles were grouped based on COVID-19 vaccine status of the female partner into those with no-exposure, 1-dose and ≥2-dose exposure. Within the exposed cohort, time-since-last-vaccination to embryotransfer- cycle (T_tr) was calculated in days. Main outcomes were mean-total-utilizable-embryos, mean-oocyteutilization- rates and cumulative-ongoing-pregnancy-rates per oocyte-retrieval-cycle, and ongoing-pregnancy and pregnancy-loss-rates per embryo-transfer cycle. The Beta-coefficient (ß) was calculated using linear regression for mean-total-utilizable-embryos and mean-oocyte-utilization-rates and adjusted-odds-ratio (OR) was calculated for cumulative-ongoing-pregnancy-rates, ongoing-pregnancy and pregnancy-loss-rates using binomial logistic regression. Influence of T_(tr) on embryo-transfer outcomes was estimated using receiver-operator-curve (ROC) analysis and cut-offs determined that influenced embryo-transfer outcomes.

Results: Mean-total-utilizable-embryos and mean-oocyte-utilization-rate per oocyte-retrieval-cycle in no-exposure, 1-dose and ≥2 dose were 2.7 ± 1.8 vs. 2.5 ± 1.9 vs. 2.7 ± 2.0, P=0.78, (ß=0.42, 95% confidence-interval (CI)=0.15 to 0.69) and 21.2 ± 13.2 vs. 25.1 ± 19.0 vs. 26.7 ± 18.8, P=0.08, (ß=3.94, 95% CI=1.26 to 6.23) respectively. Ongoing-pregnancy-rates and pregnancy-loss-rates per embryo-transfer-cycle were 27.3% vs. 24.4% vs. 32.5% (aOR=1.38, 95% CI=0.3-5.6, P=0.52), and 13.6% vs. 13.4% vs. 15.2%, (aOR=0.97, 95% CI=0.18-5.2, P=0.97) respectively. Cumulative-ongoing-pregnancy-rates per oocyte-retrieval-cycle were 36.5% vs. 34.5% vs. 35.5% (aOR=1.53, 95% CI=0.57 to 4.07, P=0.35). Median T_(tr) was 146 days (IQR: 80-220). T_(tr) negatively affected ongoing pregnancy rates for intervals <60 days (AUC=0.59, 95% CI=0.54-0.66, P<0.01). For T_(tr) >60 vs. <60 days, the aOR for ongoing-pregnancy-per-embryo-transfer-cycle was 2.85 (95% CI=1.50-5.46, P<0.01).

Conclusion: Covid-19 vaccination does not negatively influence embryological-outcomes or cumulative-ongoing-pregnancies after ART-treatments. Duration since vaccination may have a weak negative effect on embryo-transfer-outcomes performed within 60 days.