The association of post–embryo transfer SARS-CoV-2 infection with early pregnancy outcomes in in vitro fertilization: a prospective cohort study

BACKGROUND:The influence of SARS-CoV-2 infection post-embryo transfer on early pregnancy outcomes in in vitro fertilization (IVF) or intracytoplasmic sperm injection-embryo transfer (ICSI-ET) treatment remains inadequately understood. This knowledge gap endures despite an abundance of studies investigating the repercussions of preceding SARS-CoV-2 infection on early pregnancy outcomes in spontaneous pregnancies. OBJECTIVE:Our objective was to investigate the association between SARS-CoV-2 infection within 10 weeks post-embryo transfer and early pregnancy outcomes in patients undergoing IVF/ICSI treatment. STUDY DESIGN:This prospective cohort study was conducted at a single public IVF center in China. Female patients aged 20 to 39 years, with a body mass index (BMI) ranging from 18 to 30 kg/m2, undergoing IVF/ICSI treatment, were enrolled between September 2022 and December 2022, with follow-up extended until March 2023. The study tracked SARS-CoV-2 infection time (≤14 days, ≤28 days, and ≤10 weeks post-embryo transfer), symptoms, vaccination status, the interval between vaccination and embryo transfer, and early pregnancy outcomes, encompassing biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate. The study employed single-factor analysis and multivariate logistic regression to examine the association between SARS-CoV-2 infection status, along with other relevant factors, and the early pregnancy outcomes. RESULTS:A total of 857 female patients undergoing IVF/ICSI treatment were analyzed. In the first stage, SARS-CoV-2 infection within 14 days post-embryo transfer did not exhibit a significant negative association with the biochemical pregnancy rate (adjusted OR 0.74, 95% CI, 0.51-1.09). In the second stage, SARS-CoV-2 infection within 28 days post-embryo transfer revealed no significant difference in the implantation rate between infected and uninfected groups (36.6% vs 44.0%, p=0.181), and the clinical pregnancy rate showed no statistical significance after adjusting for confounding factors (adjusted OR, 0.69, 95% CI, 0.56-1.09). In the third stage, SARS-CoV-2 infection within 10 weeks post-embryo transfer showed no significant difference in the early miscarriage rate (adjusted OR, 0.77, 95% CI, 0.35-1.71). CONCLUSION:Our study suggested that SARS-CoV-2 infection within 10 weeks after embryo transfer may not be negatively associated with the biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate in patients undergoing IVF/ICSI treatment. It's important to note that these findings are specific to the target population of IVF/ICSI patients aged 20-39 years, without prior SARS-CoV-2 infection, and with a BMI of 18-30 kg/m2. This information offers valuable insights, addressing current concerns and providing a clearer understanding of the actual risk associated with SARS-CoV-2 infection after embryo transfer.