Researchers arrived at their findings by analyzing samples of amniotic sacs (fetal membranes) from 48 women after they gave birth. The report is published in the Jan. 8 online issue of the journal PLoS One.
Nearly one-third of early deliveries are associated with premature rupture of fetal membranes, and it's important to learn more about why this happens, the researchers noted.
"Complications of preterm births can have long-term health effects for both mothers and children," study author Dr. Amy Murtha, associate professor of obstetrics and gynecology at Duke University School of Medicine, said in a Duke news release.
Further research is needed to determine whether the presence of high levels of bacteria is a cause or result of fetal membrane weakening, the investigators said.
The researchers are now investigating whether certain types of bacteria may increase the risk of premature rupture of fetal membranes. Identifying such bacteria could lead to the development of preventive treatments.
"For instance, if we think that certain bacteria are associated with premature rupturing of the membranes, we can screen for this bacteria early in pregnancy," Murtha said. Treating the affected women with antibiotics might reduce their risk for this problem, she added.
The U.S. National Library of Medicine has more about premature rupture of fetal membranes.