Mom’s immune system and microbiome may help predict premature birth
Roughly 10 percent of children worldwide — an estimated 15 million babies — are born prematurely, or before 37 weeks gestation, each year. In developed countries, surviving an early birth has become more likely, thanks to the availability of intensive medical care. More than 98 percent of U.S. preemies survive infancy, according to a study published in the American Journal of Obstetrics and Gynecology in 2016, though as many as 44 percent of the youngest preemies don’t make it. Survival is least likely in nations with the fewest resources. Worldwide, complications associated with preterm birth are the leading cause of death in children younger than 5 years old. Some of the signs of inflammation linked to preterm birth differ from those found during full-term birth, says Nardhy Gomez-Lopez, a reproductive immunologist at Wayne State University. For example, in 2017, she and colleagues reported in the American Journal of Reproductive Immunology that some proteins involved in inflammation, called cytokines, were present at higher than normal levels in amniotic fluid from a subset of women who delivered preterm. The earlier the women delivered their babies, the higher the cytokine levels. Infections, which are present in at least a quarter of preterm births, could be the cause, but inflammation and cytokine levels were also elevated when no infection was found. Part of the problem with developing a predictive test is that preterm labor isn’t just one condition. Thirty years ago, preterm labor was viewed simply as regular labor that happened early, says perinatologist Roberto Romero at Wayne State, who directs the perinatology research branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Although scientists now recognize that the biology of preterm labor is distinct, they still have to grapple with the reality that it varies depending on the underlying cause. Wayne State and NICHD recently released gene activity data from the whole blood of 150 Detroit women, 71 of whom delivered preterm, and encouraged researchers to use the data to find predictors of preterm labor, as part of a crowdsourcing collaboration called the DREAM challenge. The challenge is expected to be completed in January 2020. “We are at the beginning of an exciting period,” says Romero at Wayne State. The field is now equipped to start studying preterm birth as a collection of several different syndromes and seek out treatments to address each one, he says.