Study Associates the Presence of Bacteria to Premature Water Break in Pregnant Women

A latest study links premature rupture of water sac to the presence of specific bacteria at the site.

In a novel finding, a team of Duke University researchers reveal that the presence of bacteria at the site of the fetal membrane is responsible for the water breaking prematurely during pregnancy.  The presence of bacteria is linked with the thinning of the fetal membranes.

"Complications of preterm births can have long-term health effects for both mothers and children," said study author Amy P. Murtha, M.D., associate professor of obstetrics and gynecology at Duke University School of Medicine. "Our research focuses on why the fetal membranes, or water sac, break early in some women, with the overall goal of better understanding the mechanisms of preterm membrane rupture."

The fetal membrane composed of two layers- the amnion and chorion- plays a major role in maintaining the pregnancy through the gestation period. But when this amniotic sac breaks before the 37 weeks of gestation period, it is called as the Preterm Premature Rupture of Membranes (PPROM) and nearly one-third of all early deliveries are associated with this condition.

Studies conducted earlier by the same research team revealed that in the presence of an infection, the chorion suffers from excess cell death and this cell layer is thinner in those who face PPROM.  In those with infected fetal membranes, the cell death in chorion layer was high, clearly indicating the role of the bacteria in causing PPROM.

In the present study, the researchers analyzed the chorion membrane sample in order to identify a pattern of the bacterial presence and also its link with the thinning of chorion. Membrane samples of 48 women were collected that included PPROM, preterm and term women.

The researchers noticed that in all women the chorion membrane was thin at the rupture site than the distant site. They also noticed the presence of bacteria in all fetal membranes, which contradicted the traditional thought of fetal membrane being the most sterile environment. At the rupture site the concentration of bacteria was high.

In the study subjects the concentration of the bacteria was inversely linked with the chorion thinning; higher the bacterial count, thinner the layer.

"We still know little about changes occurring within the fetal membrane in the presence of bacteria, but our data suggest the chorion and its thinning may be the battleground for these changes," Murtha said.

The team is currently trying to identify the bacteria and also determine if any particular bacteria is present in PPROM women.

The finding was documented in the journal PLOS ONE.