The effect of intravenous remdesivir on endometrial receptivity in female mice.

OBJECTIVE: Pregnant women with coronavirus disease 2019 (COVID-19) are more likely than nonpregnant women to require admission to an intensive care unit, and many may require antiviral therapy. Remdesivir, an antiviral drug used to treat COVID-19, may exert toxic effects on specific tissues and organs. Therefore, this study investigated the effects of remdesivir on endometrial tissue in pregnant female mice. METHODS: Thirty female Naval Medical Research Institute (NMRI) mice were divided into five groups. The control group received no treatment, and the sham group received the remdesivir solvent, dimethyl sulfoxide. The 2-, 4-, and 8-mg groups received the corresponding doses of remdesivir. Treatment continued for 10 days. After injection and mating, the presence of a vaginal plug was considered to indicate gestational day 1. On gestational day 4.5, uterine tissue damage, pinopode status, serum estradiol levels, and tissue expression of interleukin-6 and interleukin-1β were examined. RESULTS: Serum estradiol levels and interleukin-6 expression in endometrial tissue decreased in a dose-dependent manner after remdesivir treatment. Remdesivir treatment was also associated with fewer uterine pinopodes and histological evidence of endometrial tissue injury (p<0.05). CONCLUSION: In pregnant mice, remdesivir reduced serum estradiol levels, decreased the number of endometrial pinopodes, and suppressed interleukin-6 expression. These findings suggest that remdesivir may adversely affect the endometrium and potentially compromise implantation; however, direct functional validation is required.