Asymptomatic, mild COVID-19 at frozen embryo transfer does not worsen pregnancy outcomes

Key takeaways:

• Uninfected and infected women undergoing frozen embryo transfer had no differences in ongoing, biochemical and clinical pregnancy rates.
• Researchers found no significant tie between infection and pregnancy.

Women with asymptomatic or mild COVID-19 infection at the time of frozen embryo transfer did not experience significant adverse early pregnancy outcomes, researchers reported in BMC Pregnancy and Childbirth.

“Given the challenge of swiftly eradicating infectious diseases and the prospect of their enduring coexistence, it is imperative to acknowledge that patients severely affected by COVID-19 cannot undergo immediate assisted reproductive therapy treatments,” Yiling Ko, MD, of the International Peace Maternity and Child Health Hospital at Shanghai Jiao Tong University School of Medicine, Shanghai, and colleagues wrote. “Yet, questions persist regarding the potential risks associated with asymptomatic or mild COVID-19 infection during the pandemic.”

Ko and colleagues conducted a retrospective analysis of 709 cases of women undergoing frozen embryo transfer from October 2022 to January 2023, when there was a significant COVID-19 infection surge in Shanghai. All women had a first COVID-19 infection around the time of frozen embryo transfer and not before oocyte retrieval. Researchers categorized women based on infection timing: uninfected, at least 60 days or less than 60 days before frozen embryo transfer, 0 to 14, 15 to 28 or 29 to 70 days after frozen embryo transfer.

By study conclusion, the infection rate was 78.28% in this population.

Researchers observed no significant differences in ongoing pregnancy rates, biochemical pregnancy rates and clinical pregnancy rates for uninfected women, women infected 60 days or more before frozen embryo transfer, women infected less than 60 days before frozen embryo transfer or for women infected 0 to 14 days after frozen embryo transfer.

In addition, early spontaneous abortion rates across all groups were not significantly different.

When adjusting for potential influencing factors, researchers noted no significant correlation between infection and ongoing pregnancy. Factors significantly correlated with ongoing pregnancy were age at the time of oocyte collection (OR = 0.948; 95% CI, 0.909-0.989), blastocyst vs. cleavage stage transfer (OR = 1.72; 95% CI, 1.174-2.52) and the number of embryos transferred (OR = 1.955; 95% CI, 1.346-2.839).

“Our study, carried out during a period when the virulence of the SARS coronavirus had weakened but widespread transmission persisted, suggests that asymptomatic or mild COVID-19 infections occurring around the time of frozen embryo transfer do not significantly impact early pregnancy outcomes,” the researchers wrote. “Consequently, it may not be necessary for individuals to postpone their pregnancy plans due to the risk of asymptomatic or mild COVID-19 infections.”