A research team led by the Yale School of Public Health has found that many pregnant women in low-income areas have to travel farther than their peers to reach the nearest hospitals to deliver their babies—and the gap in accessible health care appears to be growing.

The findings are published in the Journal of Perinatology.

“This study uncovered that travel distances to a hospital obstetric unit for many economically disadvantaged women has actually increased over a 10-year period and that the need for hospital-based obstetric care is even more acute,” said lead author Peiyin Hung, PhD, a postdoctoral associate at Yale School of Public Health. “Our findings suggest that residential proximity to hospital obstetrics and neonatal care settings needs to be taken into account as travel burden might place these vulnerable women and their babies at risk.”

A travel distance of more than 30 miles to reach hospital obstetric care is considered a geographic barrier to specialized childbirth services and is a factor in unhealthy birth outcomes, Hung said. Since recent hospital obstetric unit closures studies have found that rural hospitals are fighting with low-birth volume, staffing, and financial distress, Hung and her co-authors were interested in quantifying how far rural and urban women had to travel to get the closest hospital obstetric units. In the study, the team measured travel distances in road miles for over 1.2 million women who had childbirth hospitalizations in nine geographically dispersed states in either 2002 or 2013.

Each woman’s home zip code was matched to the nearest hospital, based on the one-way driving distances. Hung and her team looked at changes in residential proximity to two care settings—obstetrics and advanced neonatal services—and found travel distances to a hospital with obstetric or advanced neonatal services were getting farther and farther for women in not only rural but also lower-income communities. By 2013, the distance from a rural pregnant woman’s home to the nearest hospital obstetric unit grew to as high as 143 miles—and the distance to the nearest advanced neonatal care unit was up to 190 miles.

“This study represents an important step toward identifying the need for future study of the effects of travel distances to the closest hospital care settings on disparities in maternal and child outcomes, as long travel distances may place mothers and neonates—particularly for those who need higher acuity care—at risk of severe morbidity and other adverse outcomes,” said Hung. “Our future analyses will include examining when the loss of local hospital obstetric services would become an issue to mothers and births, by their residential proximity prior to the services loss.”

Hung collaborated on the study with researchers at the University of Minnesota.