A Study on the Association Between Vaginal Microecology Imbalances During Pregnancy and the Risk of Spontaneous Preterm Birth: A Prospective Cohort Study

Abstract Background Spontaneous preterm birth remains a paramount challenge in obstetrics with potential adverse implications for maternal and neonatal health. The vaginal microecology during pregnancy plays a pivotal role in orchestrating normal parturition, and its dysbiosis is associated with an escalated risk of Spontaneous preterm birth. Methods A prospective study encompassing 79 pregnant women was conducted to elucidate the nexus between gestational vaginal microecology imbalances and the susceptibility to preterm birth. Based on pregnancy outcomes, participants were stratified into preterm and term groups. At the 24th gestational week and close to parturition, vaginal secretions from the pregnant women were both qualitatively and semi-quantitatively assessed in accordance with the clinical consensus on vaginal microbiota evaluation. Results Significant disparities were discerned between the preterm and term cohorts, notably regarding the lactobacillus proportion and the Nugent score and Aerobic Vaginitis score. By the 24th gestational week, the preterm group exhibited a pronounced decrement in lactobacillus proportion coupled with elevated Nugent score and Aerobic Vaginitis score. Despite interventions at the 24th gestational week for those with detrimental vaginal environments, which significantly improved Nugent score and Aerobic Vaginitis score by term, the lactobacillus proportion did not show corresponding recovery. Conclusions The study underscores a tangible association between diminished lactobacillus proportion, heightened Nugent score, and Aerobic Vaginitis score at 24 weeks of gestation, and an augmented Spontaneous preterm birth risk. These metrics offer pivotal insights for clinical practice concerning preterm birth susceptibility and emphasize the importance of preserving a healthy vaginal microbiota milieu.