Vaginal dysbiosis increases risk of preterm fetal membrane rupture, neonatal sepsis and is exacerbated by erythromycin.

Plain Language Summary

Preterm premature rupture of the membranes (PPROM) is a pregnancy complication in which the amniotic sac ruptures before week 37 of the pregnancy, leading to an increased risk of infection and premature birth. Women who experience PPROM are usually given antibiotics to help prevent infections which, left untreated, could endanger their babies’ lives. It is thought that disturbances in the mum’s vaginal bacteria may be related to the risk of PPROM. In this study, researchers examined the vaginal bacteria of women with PPROM, before and after antibiotic treatment. A total of 250 pregnant women who had been identified as at risk of a premature birth were included in the study. Disturbance of the normal vaginal bacteria, characterised by low levels of Lactobacillus, was present in a third of women who went on to develop PPROM. This disturbance of the normal vaginal bacteria was made worse by antibiotic treatment particularly in women initially colonised by Lactobacillus spp. Lower levels of Lactobacillus and increased abundance of Sneathia spp. were associated with an increased likelihood of funisitis (inflammation of the umbilical cord) and sepsis in the newborn. The authors concluded that the composition of the vaginal microbiota is a risk factor for PPROM and is associated with unfavourable short-term outcomes for the mother and newborn. This highlights vaginal microbiota as a potentially modifiable risk factor for PPROM and they suggest that the routine use of antibiotics such as erythromycin for PPROM should be re-examined.