AUTHOR=Ji Li , Peng Chen , Bao Xueyun 

TITLE=Effect of vaginal flora on clinical outcome of frozen embryo transfer

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=Volume 12 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.987292

DOI=10.3389/fcimb.2022.987292

ISSN=2235-2988

ABSTRACT=Objective: Vaginal microbiome imbalance is a high risk factor for premature birth, and is closely related to female pelvic inflammation and sexually transmitted diseases. The effect of vaginal microbiome on the outcome of assisted reproductive technology is still unclear. In this study, the vaginal microbial composition and the pregnancy outcome of frozen embryo transfer (FET) was investigated. Methods:  From October 2020 to December 2021, 275 FET cycles were selected from the center of reproductive medicine of Nantong University affiliated Hospital. Vaginal secretions were collected on the day of endometrium transformation, and smears were Gram stained. According to the Nugent score they were divided into three groups, including normal group, intermediate group and dysbiosis group. The clinical outcomes of each group were compared. Results: In 275 FET cycles, the embryo implantation rate, clinical pregnancy rate and ongoing pregnancy rate in the normal group (66.9%,84.3% and 83.1%) were significantly higher than those in  the intermediate group (45.5%, 57.3% and 49.3%) and in dysbiosis group (29.6%, 34.2% and 27%). The differences were statistically significant (P<0.01). When compared the pre-clinical pregnancy loss rate and the miscarriage rate, the normal group (1.3% and 1.3%) was significantly lower than those in the intermediate group (20.4% and 14.0%) and the dysbiosis group (25.5% and 21.1%), the difference was statistically significant (P<0.01), but there was no significant difference between the intermediate group and dysbiosis group (P>0.05). Conclusion: Nugent score is directly related to the clinical outcome of FET. The Lactobacilli-dominant vaginal flora was a favorable factor for the good clinical outcome of FET, while asymptomatic bacterial vaginosis had a negative correlation with the outcome of FET.