Fig. 3

Community state types (CSTs) and risk of recurrent sPTB. A Heatmaps displaying the relative abundance of the most abundant 20 vaginal species in early and late pregnancy. Hierarchical clustering of Jensen-Shannon distances with Ward linkage was used to determine six CSTs: IA (L. crispatus), IB (L. crispatus and L. iners), II (L. gasseri), III (L. iners), IVA (Gardenerella), and IVB (diverse non-L. species). The outcome of birth is indicated below the heatmap. B Barplot comparing the prevalence of CSTs between the preterm and term groups in early and late pregnancy. C Kaplan-Meier survival plot Kaplan-Meier survival plot comparing gestation at delivery between CST III and CST IA in the early stage; between CST IVA or CST IVB and CST IA in late stages. P-values estimated using Cox proportional hazard regression models. Statistical significance is shown as \(^{**}\)P value < 0.01, \(^{***}\)P value < 0.001