Excessive formation of calcium crystal deposits in the amniotic fluid may be a reason why some pregnant women suffer preterm premature rupture of the membranes (PPROM) leading to preterm delivery, says a new study.
The new study by researchers at Yale School of Medicine is a key breakthrough in solving the mystery of preterm birth, a leading cause of death and permanent disability in newborns.
Infection, maternal stress and placental bleeding can trigger some preterm deliveries, but the cause of many other preterm deliveries remains unknown.
In these cases, women experience early contractions, cervical dilation and a torn amniotic sac.
Yale researchers investigated the idea that calcification-excessive buildup of calcium-of the fetal membranes may lead to PPROM and preterm birth.
Scientists know that calcifying nanoparticles are involved in many degenerative conditions including arthritis and atherosclerosis.
"We wondered whether they could also be responsible for damage to the fetal membranes in pregnant women," first author Lydia Shook said.
Shook and her co-authors used a stain to look for calcium deposits in placental and fetal membrane tissue from patients with PPROM and preterm birth, as well as full-term deliveries.
They used a sterile culture technique to determine whether amniotic fluid can form nanoparticles. They then exposed fetal membranes to the cultured nanoparticles to determine their ability to induce cell dysfunction, damage and cell death.
The team found evidence of calcification of fetal membranes collected from preterm deliveries. Fetuin, one of the major proteins involved in nanoparticle formation, was found in these deposits.
Levels of fetuin in amniotic fluid were lower in women who delivered with PPROM compared to those who delivered early with intact membranes.
"This preliminary evidence suggests that amniotic fluid has the potential to form nanoparticles and deposit them in the fetal membranes," said Shook.
The findings will be presented in an abstract at the Society for Maternal-Fetal Medicine Scientific Sessions on February 10 in San Francisco, California.