The Vaginal Microbiota in Early Pregnancy Identifies a Subset of Women at Risk for Early Preterm Prelabor Rupture of Membranes and Preterm Birth

AbstractSpontaneous preterm birth (sPTB) can occur when vaginal bacteria gain access to the amniotic cavity. Thus, the predictive value of the vaginal microbiota for sPTB has been investigated, yet results have been inconclusive. Here, we report the largest study of the vaginal microbiota using longitudinal sampling of 257 cases and 514 controls (2,976 samples). Associations between the microbiota and sPTB were limited to cases of early (delivery <34 weeks) preterm prelabor rupture of membranes (PPROM). Starting with early gestation, microbial diversity was higher in early PPROM cases than controls, as were the relative abundances of Anaerococcus, Mobiluncus, Prevotella, and Sneathia. Random forest models based on data collected before 28 weeks predicted early PPROM [AUC=0.62(0.51−0.73)], while data collected by 24 weeks predicted PPROM with delivery <30 weeks [AUC=0.68(0.53-0.84)]. Therefore, monitoring of the vaginal microbiota profile may have clinical utility to identify a subset of women who will deliver a preterm neonate.