Bacteria at the site of a fetal membrane rupture could explain why some women's water breaks early.
"Complications of preterm births can have long-term health effects for both mothers and children," study author Amy P. Murtha, M.D., associate professor of obstetrics and gynecology at Duke University School of Medicine, said in a statement. "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 is composed of "two fetal cell layers, the amnion and chorion," the news release reported. Both work to keep a healthy pregnancy throughout gestation. Almost all cases of the water breaking early are linked to preterm premature rupture of membranes (PPROM).
The researchers found chorion has a higher rate of cell death when exposed to a bacterial infection. The team also noticed women who experienced PPROM tended to have a thinner membrane wall. Cell death within the chorion layer was highest in women who experienced both bacterial infection and PPROM.
The research team looked at chorion membrane samples from 48 women who had recently given birth. The team compared the thickness of the chorion layer as well as bacterial presence at sites both on and far away from the rupture site
In all of the study subjects the chorion was thinnest at the rupture site, however the thinning was more prominent in women who had experienced PPROM; in these patients the thinning was not isolated to the rupture site.
"The researchers then looked to see if bacteria were present in the membranes and whether bacteria levels correlated with the thinning of the cell layers in the membranes. Interestingly, bacteria were present in all fetal membranes, refuting the traditional understanding that fetal membranes are sterile environments. The amount of bacteria present at the rupture site was higher, which the researchers were not surprised to find," the news release reported.
The team found the more bacteria that were present the thinner the chorion membrane tended to be overall. The team did not determine if the bacteria presence proved a
"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 researchers' next steps will be to pinpoint exactly what bacteria is present on the chorion membrane.
"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. We then might be able to treat affected women with antibiotics and reduce their risk for PPROM," Murtha said. "Our research is several steps away from this, but it gives us opportunities to explore potential targeted therapeutic interventions, which we lack in obstetrics."
