Pfizer SARS-CoV-2 BNT162b2 mRNA vaccination (BNT162b2) has no adverse effect on elective oocyte cryopreservation outcomes

RESEARCH QUESTION: Do elective oocyte cryopreservation outcomes in women 1–13 months after SARS-CoV-2 vaccination alter compared with unvaccinated women and do different time intervals between vaccination and ovarian stimulation impact these outcomes? DESIGN: This retrospective cohort study, conducted in a university-affiliated IVF centre, included 232 elective oocyte cryopreservation cycles of vaccinated and unvaccinated patients, without previous infection with the SARS-CoV-2 virus, between December 2020 and January 2022. Two control groups – pre-pandemic (January 2019 to February 2020) and intra-pandemic (December 2020 to January 2022) unvaccinated groups – were compared with the vaccinated group, further divided into four subgroups (under 3, 3–6, 6–9 and 9–13 months). The primary outcome was the elective oocyte cryopreservation cycle outcomes – number of retrieved and number of mature oocytes. RESULTS: The vaccinated group demonstrated comparable outcomes with regards to number of retrieved and mature oocytes compared with the pre-pandemic and intra-pandemic unvaccinated groups (12.6 ± 8.0 versus 13.0 ± 8.2 and 12.5 ± 7.4 retrieved and 10.1 ± 6.9 versus 9.5 ± 6.4 and 10.1 ± 6.3 mature oocytes, respectively; not significant for both). Similar results were noted in a comparison between the intra-pandemic unvaccinated group and the four vaccinated subgroups. No correlation was found between the parameter of days from vaccination and cycle outcomes. Similarly, analysis of covariance showed no association between vaccination status and timing and number of mature oocytes. CONCLUSIONS: The SARS-CoV-2 vaccination does not alter the outcomes of elective oocyte cryopreservation procedures. This is true even in a relatively long time interval of 9 to 13 months from vaccination.