Mixed vaginitis is caused by the simultaneous presence of at least two vaginal pathogens, contributing to an abnormal vaginal milieu and leading to vaginal symptoms and signs. However, associations between symptoms and microbes have not been clearly elucidated. Therefore, mixed vaginitis is an inflammatory condition that remains underrecognized. Mixed vaginitis generally involves the formation of mixed biofilms. The specific characteristics of mixed biofilms, especially their enhanced drug resistance and their ability to evade components of the host immune response, make them of high clinical importance. This review summarizes the relevant clinical data to improve clinical knowledge about mixed vaginitis.

Objective：To clarify the epidemiological characteristics, risk factors, clinical symptoms and signs, laboratory features, and pregnancy outcomes of women with mixed vaginitis during late pregnancy. Methods：The study population consisted of 1103 women in late pregnancy who attended the Tianjin Medical University General Hospital from November 2019 to September 2020. Results：The incidence rate of mixed vaginitis during late pregnancy is 4.1% (44/1075). The independent risk factors for women with mixed vaginitis in late pregnancy are a positive glucose tolerance test (OR = 2.697, 95% CI 1.293-5.625) and a history of vaginitis during pregnancy (OR = 2.276, 95% CI 1.030-5.032). Compared with women with single vaginitis, women with mixed vaginitis only have statistically significant differences in the yellow discharge (77.3% vs. 58.9%) and malodor (40.9% vs. 22.7%) (P＜0.05), so they are easily confused with single vaginitis in clinical symptoms and signs. Compared with women with single vaginitis, women with mixed vaginitis have a significant difference in pH＞4.5 (72.7% vs. 36.2%) and WBC＞10/hpf (81.8% vs. 38%) in laboratory examination(P＜0.05). Therefore, laboratory diagnosis is the main method to distinguish single and mixed vaginitis. Compared with women without vaginitis, women with mixed vaginitis have an increased incidence of postpartum puerperal infections (6.8% vs. 1%; P＜0.05). Conclusions：Mixed vaginitis in late pregnancy leads to an increased incidence of puerperal infections. Therefore, more attention should be paid to the early intervention of mixed vaginitis during pregnancy to prevent adverse pregnancy outcomes.