The correlation between vaginal microbiome dysbiosis and recurrent spontaneous abortion.

In recent years, the role of the vaginal microbiota in pregnancy maintenance has garnered increasing attention. Extensive research indicates that vaginal dysbiosis is closely associated with various adverse pregnancy outcomes, including ectopic pregnancy, miscarriage, preterm birth, and premature rupture of membranes. Recurrent spontaneous abortion (RSA) affects approximately 1-5% of women of childbearing age and has a complex etiology, with infection implicated in about 4% of cases. This systematic review examines the compositional characteristics of the vaginal microbiota, its dynamic changes during pregnancy, and the underlying mechanisms linking it to RSA. It focuses on the protective role of lactobacilli, ascending pathogen infection, and local immune regulation, aiming to provide a novel theoretical foundation for the prevention, risk prediction, and personalized treatment of RSA.