Two-Thirds of Women of Reproductive Age Face Preventable Birth Defect Risks

A new analysis of U.S. women of reproductive age has revealed a concerning but important truth: two thirds of women between the ages of 12 and 49 have at least one modifiable risk factor that increases the chance of serious birth defects. The study, published in the American Journal of Preventive Medicine and led by Dr. Arick Wang of the Centers for Disease Control and Prevention, draws on data from the National Health and Nutrition Examination Survey (NHANES) collected between 2007 and 2020. The findings underscore the urgent need to identify and address health risks before pregnancy to protect the health of future children.

Birth defects such as congenital heart defects, orofacial clefts, and neural tube defects are among the most common in the United States. These conditions arise from disruptions during embryonic development and can vary in severity. According to the research, congenital heart defects affect about 100 in every 10,000 live births, orofacial clefts about 16 per 10,000, and neural tube defects roughly 7 per 10,000. While some causes are genetic or unchangeable, others—such as poor nutrition, obesity, diabetes, and tobacco use—are within the realm of prevention.

Dr. Wang explains that the pathogenesis of these birth defects is multifactorial, meaning both genetic and environmental factors play a role. However, epidemiological studies have consistently pointed to several changeable contributors: folate insufficiency, vitamin B12 deficiency, pregestational diabetes, pregestational obesity, tobacco exposure, and even food insecurity. These factors can disrupt metabolic pathways critical for cell growth and replication, such as the one-carbon cycle metabolism, raising the risk of abnormalities during pregnancy.

Among the key findings, low folate status remains a significant concern. Although folic acid fortification of enriched cereal grains has been in place in the U.S. since the 1990s, one in five women of reproductive age still have low red blood cell folate concentrations. Even more concerning, nearly four out of five women do not consume the recommended 400 micrograms of folic acid daily to help prevent neural tube defects. About 72 percent of women also reported not taking supplements containing folic acid. Still, progress has been made: the proportion of women with low folate levels decreased from 23.4 percent in 2007 to 17.9 percent in 2020, preventing an estimated 1,300 neural tube defects annually.

Diabetes presented another clear risk. Nearly 5 percent of women in the study population had diabetes, with 3.5 percent experiencing poor glycemic control due to either undiagnosed or unmanaged conditions. Since uncontrolled blood sugar before and during pregnancy is strongly linked with birth defects, this finding points to the need for greater screening and management support for women of childbearing age.

Obesity also emerged as a major factor, with nearly one in three women of reproductive age living with obesity. Combined with food insecurity, which was reported by 7.3 percent of the women surveyed, the findings reveal the complex interplay between access to healthy food, weight management, and long-term health outcomes for both mothers and babies.

Tobacco exposure remains prevalent as well. About one in five women of reproductive age showed elevated serum cotinine levels, a biomarker for nicotine exposure. This figure includes not only smokers but also women exposed to vaping or secondhand smoke, highlighting a persistent and preventable risk that public health programs must continue to address.

Dr. Wang emphasizes that while the numbers show widespread risk, they also offer a clear opportunity. “Every growing family hopes for a healthy pregnancy and healthy baby. Understanding modifiable risk factors for birth defects helps families, healthcare providers, and public health professionals make data-informed decisions that can lead to healthier pregnancies and babies,” he said.

By shining a spotlight on preventable contributors to birth defects, the study reinforces the importance of early intervention, education, and access to health resources. Women of reproductive age are not powerless against these risks—through better nutrition, regular medical care, smoking cessation, and improved diabetes management, the likelihood of birth defects can be reduced. The research offers a hopeful reminder that with continued public health efforts and individual awareness, healthier pregnancies and healthier babies are within reach.