Preterm birth leads to a host of complications that can last a lifetime, from cerebral palsy to chronic lung disease—not to mention very stressful and expensive NICU stays and a decreased rate of survival. And in the Unites States, one in 10 babies is born too soon. So understandably, doctors have been working very hard to determine what makes a woman more at risk for delivering early. Now, they've accomplished a huge breakthrough by discovering six genes that raise the risk of delivering early.
The new study, published in the New England Journal of Medicine and led by an international team of researchers, was the largest DNA analysis of pregnant women ever—more than 44,000. "It was known that genetic factors contribute about 30 to 40 percent of the risk for preterm birth and overall regulation of the duration of pregnancy, and this genetic risk was largely transmitted by the mother's genes," Dr. Louis Muglia, MD, PhD, who coordinated the study and is the co-director of the Perinatal Institute at Cincinnati Children's and principal investigator of the March of Dimes Prematurity Research Center-Ohio Collaborative, tells Parents. "What was not known was what specific maternal genes or regions of the mother's DNA are responsible."
Dr. Muglia says the study has laid a strong foundation for understanding human pregnancy by identifying six gene regions that regulate birth timing and risk for early delivery. The next step is to figure out exactly what these six genes do to cause preterm birth, so doctors can develop treatments. "For example, the region around [gene] WNT4 likely affects the function of the lining of the uterus, which allows the embryo to implant and establish a healthy pregnancy," he says. So, a woman's uterine cells could be collected and analyzed to help establish her risk.
"The other gene we have a strong idea about is EEFSEC, which is involved in selenium metabolism," Dr. Muglia says. Selenium helps regulate inflammation and cellular aging, which if uncontrolled could lead to premature birth. "This finding suggests that we look to see if some women with preterm birth actually have low selenium levels and might benefit from selenium supplementation," he says. If so, selenium may even be added to prenatal vitamins, Stacey D. Stewart, president of the March of Dimes, tells Parents. But before you run out to the drugstore for selenium supplements, more research is needed to see if this would be an effective intervention.
The other four genes are involved in immune function, cardiovascular function and metabolism, Dr. Muglia says. "By now focusing on these genes, which were not previously known to be involved in the control of the duration of pregnancy, we will certainly learn in detail how they act and use that information to improve pregnancy outcomes," he says.
Stewart says half of premature births are of unknown cause, although this study puts doctors on the path to understanding. "This research and gene discovery may lead to new nutritional, pharmaceutical, or other lifestyle modifications for prevention of preterm birth," Stewart says. But these are far in the future, so what can preggos do now to reduce their risk?
The other half of early births have known factors involved, like smoking, poor nutrition, diabetes, high blood pressure, or a history of miscarriage or early delivery. Because of this, "it's important for pregnant women to pay attention to their health before and during pregnancy," Stewart says. In order to meet the March of Dimes' goal to reduce the premature birth rate from 9.8 percent to 5.5 percent by 2030, here are some things she says you can do now: