The association between vaginal bacterial composition and miscarriage

To characterise vaginal bacterial composition in early pregnancy and investigate its relationship with first and second trimester miscarriages, the study conducted prospective profiling on 161 pregnancies by using 16S rRNA gene?based metataxonomics from 5 weeks? gestation in pregnancies ending in miscarriage (78) or uncomplicated term deliveries (83) matched for age, gestation and body mass index. Relative vaginal bacteria abundance, diversity and richness were measured and compared among cohorts. RESULTs: Vaginal bacterial composition in first trimester miscarriage is associated with reduced Lactobacillus spp. abundance and is independent of vaginal bleeding. Incomplete/complete miscarriage associated with higher proportions of Lactobacillus spp.?depleted communities compared with missed miscarriage. Early pregnancy vaginal bacterial stability was similar between miscarriage and term pregnancies.