Previse preterm birth in early pregnancy through vaginal microbiome signatures using metagenomics and dipstick assays.

Annually, in India, 13% of all newborns are preterm, accounting for 23.4% of preterm birth (PTB) globally. The composition and diversity of the vaginal microbiome have a notable degree of ethnic inequality. For understanding differences in vaginal microbiome composition and functions between adverse and normal pregnancy, we have collected, processed and sequenced 600 high vaginal swab (HVS) samples across the three trimesters of pregnancy from 140 women who delivered at term and 60 women who delivered PTB, adopting a targeted metagenomics approach. The microbial signatures in HVS samples showed Lactobacillus genera to be highly abundant in term birth (TB), while in early pregnancy the abundances of Gardnerella, Atopobium, and Sneathia were found to be high in PTB. We further extended our analysis, identified specific microbial genomic signatures, and developed a dipstick assay for rapid identification of PTB-associated microbiota in HVS samples in low-resource settings.