A study involving more than 50,000 women could lead to new ways to prevent the leading cause of death worldwide for children under five years old.
The study, coordinated by Louis Muglia, MD, of the Perinatal Institute at Cincinnati Children's, identifies six gene regions related to preterm birth.
"Interestingly, they weren't in the areas in genes that we previously spent a lot of time thinking about," says Muglia. "I think for the first time this lays a really solid foundation for the way we think about the biology of human pregnancy."
The findings are published in the September 21 issue of the New England Journal of Medicine.
Some Key Findings
This is a beginning point. The six gene areas identified by the project serve as a launching platform for deeper research, some of which has already begun. Potential diagnostic tests, new medications, improved dietary supplements or other changes that could help more women have full-term pregnancies will require several more years of study, the authors say.
One of the gene areas identified suggests that cells within the lining of the uterus play a larger-than-expected role in the length of pregnancy, which in turn provides a new target for medications to help prevent preterm birth.
Another newly identified gene area raises important questions about how a lack of selenium—a common dietary mineral found in some nuts, certain green vegetables, liver and other meats—might affect preterm birth risk. People living in regions with low selenium in soil and diet, and people in the U.S. who live in low-income “food deserts” are most at risk of having a lack of selenium in their diets.
President of the Global Health Division of the Bill & Melinda Gates Foundation, Trevor Mundel calls the findings exciting.
"Not only did the study reveal several genes linked to preterm birth, it also identified a simple, low-cost solution – selenium supplements for expectant mothers – that, if confirmed, could save thousands of lives. It's a great example of the power of public-private partnership."
That said, Muglia says more research is needed, and planned, in this area. Pregnant women should not seek out selenium supplements on their own. Selenium is already present in many multi-vitamins, Muglia says.
A gene region found to be related to helping the uterine lining prepare for embryo implantation could improve early detection of a possible risk.
"It suggests to us that it's really some of these very early stages not late stages of the pregnancy that shape the whole risk for preterm birth," he says. "And actually, we may be able to determine a risk even if she's never been pregnant before by understanding the function of these lining cells of the uterus."
Preterm birth affects 9.6 percent of U.S. pregnancies and more than 15 million worldwide, according to the National Center for Health Statistics at the Centers for Disease Control and Prevention.
Women in the study provided saliva samples and answered questions about past pregnancies. The findings are a result of DNA analysis.