Unraveling the Links Between Diet and Preterm Birth

Our Researcher: Mary Regan, PhD, RN

By Dan Mezibov

Preterm birth is a leading cause of infant death and incurs billions of dollars per year in health costs. It occurs prior to 37 weeks of pregnancy and has been associated with long-term neurological and learning disabilities, physiological and respiratory disorders, diabetes, and organ immaturity in children. The causes are not well understood but are thought to stem from a complex interaction between biological and social factors, including human physiology, molecular biology, personal health habits, diet, and socioeconomic factors.
Disruptions in vaginal microbiota — the bacteria and other microbes that live in the vagina — have been associated with preterm birth, but precisely how the disruptions cause the problem has eluded researchers.
With a $2.5 million grant from the National Institute of Nursing Research, Mary Regan, PhD, RN, associate professor at the University of Maryland School of Nursing, and Jacques Ravel, PhD, professor at the Institute for Genome Sciences at the University of Maryland School of Medicine, are conducting a study to explore how eating habits affect the vaginal microbiota and their relationship to preterm birth. Preliminary findings suggest that poor diet may lead to changes in the composition of the microbiota, which can send signals that trigger labor. In a separately funded investigation, the team has begun to conduct feasibility testing to determine the impact that diet may have on the composition of the microbiota in the gastrointestinal tract that could send signals related to inflammation, which in turn hypothetically could increase the risk of preterm birth.
“If you look at any disease process, diet is invariably indicated,” says Regan, explaining that the foods we eat affect the structure of microbiota, which can alter processes essential to health such as vitamin synthesis and antioxidant absorption. Without enough antioxidants in the diet, Regan notes, the resulting oxidative stress can induce premature labor. Since the study began in 2014, the team has recruited more than 234 low-risk women from high-risk communities in and around Baltimore. The women, who enroll in the study prior to the 20th week of pregnancy and are followed until six weeks post-partum, provide weekly vaginal swabs and pH levels and monthly oral and stool samples. Using an iPhone app specifically designed for the study, the women report information about their health behaviors and also upload photos of the food they eat so that nutritional components can be analyzed. 
“We have an unusually low rate of preterm birth in the study, so we suspect it has become an intervention of sorts,” Regan explains. “By providing a means for the women to see what their diet looks like, it likely promotes changes in the eating and behavior that lower their risk of preterm labor and birth.” These outcomes, she points out, can provide insights into very simple interventions that could improve public health while reducing health costs.