A review study of predicting preterm birth through vaginal microbiota and cervical length

Preterm birth (PTB), defined as delivery before 37 completed weeks of gestation, remains one of the leading causes of neonatal morbidity and mortality worldwide. Despite advances in obstetric care, the global incidence of PTB has shown only modest decline, highlighting the need for improved early prediction and prevention strategies. In recent years, increasing attention has been directed toward biological markers that reflect underlying pathophysiological processes preceding spontaneous preterm labor. Among these, vaginal microbiota composition and cervical length have emerged as two of the most promising and clinically relevant predictors. The vaginal microbiota plays a critical role in maintaining reproductive tract homeostasis, immune regulation, and protection against ascending infections, while cervical length reflects structural and biochemical remodeling of the cervix that precedes labor. This review article synthesizes evidence from the last ten years to examine the role of vaginal microbiota and cervical length in predicting preterm birth. The article discusses biological mechanisms, epidemiological evidence, diagnostic methods, and the potential benefits of integrating these markers into combined predictive models. Eight figures and three tables are incorporated to enhance conceptual clarity. The findings highlight that combined assessment of vaginal microbiota profiles and cervical length offers superior predictive accuracy compared to either marker alone, supporting a more personalized and preventive approach to antenatal care