If You Gave Birth Early Once, You Need to Read This

New research says that women who delivered their first child at 37 or 38 weeks are at a much higher risk of giving birth prematurely in the future. 

Pregnant and Holding a Baby Dmitry Naumov/Shutterstock

According to new research, women who give birth to their first child early (at 37 or 38 weeks, in the context of this study) are two to three times more likely to deliver their next baby prematurely (before 37 weeks). Researchers at the University of California San Francisco analyzed data of over 160,000 women who gave birth in California between 2005 and 2011 to reach a finding that surprised even the researchers themselves.

"The magnitude of the increased risk surprised us—it really is a potent factor," the study's senior author, Laura Jelliffe-Pawlowsk, said.

It might seem as though certain women are simply at higher risk for delivering preterm—after all, plenty of lifestyle factors (like illegal drug use during pregnancy) and health conditions (high blood pressure, diabetes or a history of urinary tract infections) put women at risk for preterm delivery. However, even when researchers took these factors into account, a previous early term birth was still a huge risk factor for a subsequent premature birth. 

Researchers hope that their findings will pave the way for new policies that could reduce rates of premature birth. This is a huge deal: Preterm birth is the leading cause of infant death and can lead to lifelong neurological issues like cerebral palsy, developmental delays and vision/hearing loss. 

“We are on the edge of a new era in prematurity prevention and improving associated outcomes–there are new blood tests that can help improve identifying who’s at risk for prematurity," Larry Rand, MD, an associate professor of obstetrics, gynecology and reproductive sciences, said in a news release. "When coupled with important risk factors, like maternal conditions and previous pregnancy duration, not only do we get a more precise picture of risk, but also a more informed sense of what interventions could be most powerful to mitigate those risks.”  

"There are so few avenues to lower preterm birth rates, so I'm always thrilled when our work suggests an additional one," Jelliffe-Pawlowski said.