Preeclampsia is a hypertensive disorder of pregnancy that is life-threatening to both the mother and the fetus and is a leading cause of preterm delivery. The onset of preeclampsia typically occurs in the third trimester of pregnancy, often between 24-27 weeks gestation. During prenatal care, the obstetrician checks blood pressure and other risk indicators at each prenatal visit, but preeclampsia can come on suddenly and without warning, requiring emergency care.
Because preeclampsia remains an important unexplained and often unpredictable disease of pregnancy, Paul Winchester, MD, a professor of clinical pediatrics at the Indiana University School of Medicine and a neonatologist at Franciscan Health, in collaboration with Michael Skinner, PhD, of the Washington State University School of Biological Sciences, published a study in Environmental Epigenetics investigating pregnancies in which preterm birth — or premature birth — was caused by preeclampsia. They learned that many medical conditions can be related to underlying DNA changes, also known as epigenetic changes, in the mother.
The study’s main goal was to identify an epigenetic marker that could potentially be used to predict the mother’s susceptibility to preeclampsia-related preterm birth.
Study results showed a set of methylated DNA sites unique to women with preeclampsia-induced preterm birth. These epigenetic changes found in samples obtained from inner mouth cheek swabs could one day help predict which mothers are at risk of preeclampsia-induced preterm birth earlier in their pregnancies, before any symptoms have developed.
Epigenetic changes can result from prenatal, early-life and environmental exposures and can be familial. Skinner’s prior studies have found similar DNA methylation changes from environmental exposures in rodent models. These changes are often associated with later-life disease and can become the basis for inherited diseases. More validation studies will be needed before these findings are verified and their predictive value assessed.
“We are hopeful that an epigenetic biomarker such as this may assist obstetricians as an advanced warning system,” Winchester said. “Epigenetic biomarkers may help explain why certain women are susceptible to preeclampsia while others are not.
“I’m very grateful for the entire research team for helping make this happen. Projects like this take years, and enrolling willing patients is a very special and important part of doing a study like this. I’d also like to thank my colleagues Wade Clapp, Laura Haneline, and Edgardo Szyld for their support, as well as Patrick Clements and Emily Scott for introducing our team to new mothers who expressed interest in our study.”
The next steps for this project would be to repeat the study with a larger cohort and test biomarkers collected in early pregnancy.
“The cause of preeclampsia is still largely unknown," Winchester said. "Epigenetic and genetic factors are likely contributors to preeclampsia susceptibility, but these factors are not yet well understood. We hope that this study will help develop newer, better and more comprehensive methods for treating this disease in the future."
