Effects of SARS-CoV-2 infection during IVF treatment on embryo morphokinetics and pregnancy outcomes after fresh transfer: a prospective cohort study.

Abstract

Objectives: Prior studies have assessed the association between SARS-CoV-2 convalescence and subsequent in vitro fertilization (IVF) treatment, while the outcomes of couples infected during controlled ovarian stimulation (COS) were limited and controversial. The aim of this study was to clarify the effects of SARS-CoV-2 infection during COS on embryo morphokinetics and IVF clinical outcomes with the use of time-lapse monitoring.

Methods: We conducted a prospective cohort study of 230 couples who underwent IVF cycles between April 2023 and April 2024 in an academic fertility center. Participants were divided into four groups based on the nucleic acid testing for SARS-CoV-2 during COS: both positive (n = 31), female positive (n = 64), male positive (n = 20), and both negative (n = 115). A time-lapse imaging system was used for embryo culture. Multivariate logistic regression and generalized linear models were performed to control for potential confounders.

Results: Compared with the both negative group, the both positive group had a significantly lower cleavage rate (97.4 ± 7.7% vs. 93.6 ± 11.5%; β_adjusted = -0.04, 95% confidence interval [CI]: -0.07- -0.01) and blastocyst formation rate (85.4 ± 18.9% vs. 73.0 ± 29.4%; β_adjusted = -0.15, 95% CI: -0.28- -0.03). Embryos derived from the both positive group also presented significantly longer time to form 5, 6, 7, and 8 cells (t5-t8), as well as time to start compaction (tSC), time to morulation (tM), time to start blastulation (tSB), time to blastocyst (tB), and time to expanding blastocyst (tEB). No adverse impacts were observed on oocyte- and embryo-related outcomes in female positive or male positive group. The four groups were also comparable in live birth rate and neonatal outcomes after fresh embryo transfer.

Conclusion: SARS-CoV-2 infection in both partners affects morphokinetic parameters of embryo development with decreased cleavage rate and blastocyst formation rate, but does not influence pregnancy and neonatal outcomes after fresh embryo transfer. Our study implies that reproductive physicians should pay attention to infertile couples with SARS-CoV-2 infection during IVF treatment and should provide adequate counseling on their embryo and pregnancy outcomes.