ANN ARBOR, August 26, 2025 – A comprehensive study using data from the National Health and Nutrition Examination Survey (NHANES) reveals that two-thirds of women of reproductive age in the United States have at least one modifiable risk factor that could increase the likelihood of serious birth defects. This groundbreaking research, published in the American Journal of Preventive Medicine by Elsevier, underscores the importance of identifying and addressing these risk factors, particularly before pregnancy, to enhance public health strategies and healthcare provider interventions.
Congenital heart defects, orofacial clefts, and neural tube defects (NTDs) are among the most common structural birth defects, resulting from abnormalities during embryogenesis. These conditions have significant prevalence rates in the United States, with congenital heart defects affecting approximately 100 per 10,000 live births, orofacial clefts 16 per 10,000, and NTDs 7 per 10,000.
Understanding Modifiable Risk Factors
The study, led by Dr. Arick Wang from the Centers for Disease Control and Prevention, highlights the multifactorial nature of birth defect pathogenesis, involving both nonmodifiable and modifiable risk factors. Dr. Wang notes, “Common modifiable risk factors include food insecurity, folate insufficiency, vitamin B12 deficiency, pregestational diabetes mellitus, pregestational obesity, and exposure to cigarette smoke. These factors may contribute to birth defects through the one-carbon cycle metabolism, essential for cell growth and replication.”
Researchers analyzed data from 5,374 non-pregnant, non-lactating women aged 12–49 years, collected between 2007 and 2020, to assess the prevalence and trends of these risk factors. The findings reveal that two-thirds of these women had at least one modifiable risk factor, highlighting the widespread nature of these issues.
Significant Findings and Public Health Implications
“The invaluable NHANES health survey helped us understand health trends and concerns among the U.S. population. The most significant finding—that two-thirds of women of reproductive age had at least one modifiable risk factor—highlights how common these changeable risk factors are. The good news is that they can be lowered,” says Dr. Wang.
Since 1992, the U.S. Public Health Service has recommended a daily intake of 400µg of folic acid to prevent NTDs. Dr. Wang observes a meaningful decrease in women with low blood folate status from 23.4% to 17.9% over the study period, attributing this improvement to public health efforts like folic acid fortification of enriched cereal grains. This initiative has reportedly prevented over 1,300 NTD cases annually.
Key Risk Factors and Their Prevalence
The study identifies several key modifiable risk factors:
- Low folate status: One in five women had low red blood cell folate concentrations, and approximately 72% did not consume folic acid supplements.
- Diabetes: 4.8% of the women had diabetes, with 3.5% having uncontrolled or undiagnosed conditions.
- Obesity: Nearly one in three women were found to be obese, consistent with previous estimates.
- Tobacco use and exposure: Nearly 20% of women showed elevated serum cotinine levels, indicating tobacco exposure.
- Food insecurity: About 7.3% reported very low household food security, with prevalence decreasing as household income increased.
Moving Forward: Addressing the Challenges
The findings of this study emphasize the need for targeted public health interventions to address these modifiable risk factors. Dr. Wang concludes, “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.”
As healthcare providers and policymakers consider these findings, there is a clear opportunity to enhance educational programs and support systems for women of reproductive age. By prioritizing preventive measures and addressing these risk factors, it is possible to significantly reduce the incidence of birth defects and improve maternal and infant health outcomes.
