Birth defects are the leading cause of infant deaths in the U.S., and new research suggests that most women under 50 may have risk factors that increase the chances often before they even realize they’re pregnant.
According to the Centers for Disease Control and Prevention, about 1 in 33 babies in the U.S. are born with birth defects. A new CDC study, published Tuesday in the American Journal of Preventive Medicine, highlights five preventable or manageable risks: obesity, diabetes, smoking exposure, food insecurity, and low folate levels.
The findings are based on data from more than 5,300 women who took part in the National Health and Nutrition Examination Survey between 2007 and 2020. Researchers found that 66% of women ages 12 to 49 had at least one of these risk factors, and 10% had three or more.
“This is about awareness,” said Arick Wang, the CDC health scientist who led the study. “These risks can be lowered through steps like getting 400 micrograms of folic acid daily, eating a healthy diet, exercising, and managing blood sugar.”
Folate, a vitamin that helps the body make new cells, is especially important. Too little folate is linked to neural tube defects, which affect the brain and spine during the earliest weeks of pregnancy. Since 1998, the FDA has required folic acid to be added to enriched cereal-grain products, a move the CDC says prevents more than 1,300 neural tube defects each year. Doctors recommend anyone who is pregnant or planning to get pregnant take folic acid supplements.
Still, many risks remain unclear. “The vast majority of birth defects happen for reasons we still don’t fully understand,” said Wendy Nembhard, who directs the Arkansas Center for Birth Defects Research and Prevention. “Even when women do everything right, outcomes can still be different than expected.”
The most common risk factor in the study was obesity, affecting about one-third of the women surveyed. Scientists suspect it plays a role by disrupting insulin and glucose regulation, which can interfere with how a fetus develops. Diabetes and smoking exposure pose similar threats by affecting organ development and oxygen supply.
Food insecurity is another concern. A lack of consistent access to nutritious food can lead to vitamin deficiencies that raise the risk of birth defects. “We want to make sure people have safe places to be physically active and access to healthy foods,” said Dr. Michael Warren, chief medical and health officer of March of Dimes.
Public health officials say the findings should be a call to action. Mississippi, for example, recently declared a public health emergency over its high infant mortality rates and promised to address “care deserts,” where women lack access to obstetricians.
The report also comes as the CDC faces uncertainty about its future resources. Earlier this year, the Department of Health and Human Services announced 2,400 job cuts at the agency. A federal judge later blocked layoffs in certain programs, including the National Center on Birth Defects and Developmental Disabilities, which produced the new study. But at least 600 CDC employees are still expected to lose their jobs.
“This research is too important to lose,” Nembhard said. “We’re encouraged the study has continued, especially at a time when women and babies need this information the most.”
