Bacterial presence during pregnancy linked to premature birth

A new research has suggested that a high presence of bacteria at the site where foetal membranes rupture may be the key to understanding why some pregnant women experience their "water breaking" prematurely.

The findings by researchers at Duke University School of Medicine suggested that the bacterial presence is associated with thinning of the foetal membranes. However, more research is needed to understand whether bacterial presence is a cause or consequence of foetal membrane weakening.

Study author Amy P. Murtha said the research focuses on why the foetal membranes, or water sac, break early in some women, with the overall goal of better understanding the mechanisms of preterm membrane rupture.

Composed of two foetal cell layers, the amnion and chorion, foetal membranes play an important role in maintaining pregnancy through gestation. Nearly one-third of all early deliveries are associated with the water breaking in what's known as preterm premature rupture of membranes, or PPROM.

Previous research from Murtha and her colleagues demonstrated that the chorion has more cell death when infection is present, and that this cell layer may be thinner in women who experience PPROM.

In the current study, the researchers prospectively examined chorion membrane samples to identify a pattern of bacterial presence and association with chorion thinning.

It was found that among PPROM subjects, bacteria counts were highest compared to all other groups at both the rupture site and distant from the rupture site. Among all subjects, bacterial counts were inversely correlated with chorion thinning: the more bacteria present, the thinner the chorion.

The study was published in the journal PLOS ONE.