Role of Reproductive Tract Infections in Spontaneous Abortion: A Review

This review aims to summarize the association between reproductive tract infections and spontaneous abortion, clarify the underlying molecular mechanisms, and provide a scientific basis for clinical screening and targeted interventions.

The electronic database PubMed was searched for studies published before April 2026. Keywords included "spontaneous abortion," "Recurrent Spontaneous Abortion," "early spontaneous abortion," "Early Pregnancy Loss," "late spontaneous abortion," "late abortion," "miscarriage," "reproductive tract infections," "bacterial vaginosis," "Chlamydia trachomatis," "Ureaplasma urealyticum," "Ureaplasma parvum," "Human Papillomavirus," "Herpes Simplex Virus," "Cytomegalovirus," "Vulvovaginal Candidiasis," "Trichomonas vaginitis," and "vaginal dysbiosis." Relevant references from retrieved manuscripts and review articles were also searched manually to ensure comprehensive coverage of eligible studies.

Reproductive tract infections are key factors for spontaneous abortion, with bacterial vaginosis, Chlamydia trachomatis, Ureaplasma urealyticum, and Ureaplasma parvum showing significant associations. Vaginal dysbiosis interacts with reproductive tract infections, potentially promoting spontaneous abortion through inflammatory responses, disrupted maternal-fetal immune tolerance, and direct placental damage. The association between viruses (e.g., Human Papillomavirus, Herpesvirus infections), Mycoplasma hominis, and Trichomonas vaginalis with spontaneous abortion remains controversial.

During pregnancy, maintaining vaginal microbiota balance, routine screening for infections of the reproductive tract, and timely execution of targeted interventions are critical for spontaneous abortion. Future research should focus on large-scale prospective studies to clarify the precise mechanisms of pathogen transmission and to optimize intervention strategies.