Two-thirds of women have a modifiable risk factor for birth defects

Investigators report that two out of three women of reproductive age in the USA have at least one modifiable risk factor for birth defects.

The findings were published on August 26, 2025 in the American Journal of Preventive Medicine.

The birth defects included in the study were congenital heart defects, orofacial clefts, and neural tube defects (NTDs). These conditions are among some of most common birth defects in the United States, with prevalences of about 100 per 10,000 live births, 16 per 10,000 live births, and 7 per 10,000 live births, respectively.

Lead investigator Arick Wang, PhD, Division of Birth Defects and Infant Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention in Atlanta, said, “The pathogenesis of these common birth defects is multifactorial and includes both nonmodifiable and modifiable risk factors. Common modifiable risk factors have been identified through epidemiological studies and include food insecurity, folate insufficiency, vitamin B12 deficiency, pregestational diabetes mellitus, pregestational obesity, and exposure to cigarette smoke.”

The investigators extracted and analyzed data from the (USA) National Health and Nutrition Examination Survey (NHANES). They found that among 5,374 women of reproductive age (12-49) approximately 66.4% had at least 1 known modifiable risk factor.

Of the total group, 6.7% reported very low food security, 33.8% were obese, 4.8% had diabetes, 18.8% had smoking exposure, and 19.5% had red blood cell folate concentrations below the threshold (748 nmol/L) for optimal neural tube defect prevention.

Over the period studied (2007 to 2020), the percentage of women of reproductive age with at least 1 risk factor rose from 65.3% to 69.5%.

The authors concluded, “Approximately 2 of 3 women of reproductive age in the U.S. have pre-existing modifiable risk factors for birth defects. Implementation of preconception health care could help reduce the prevalence of known risk factors and improve birth outcomes.”

Wang added, “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.”