Trends and disparities in anencephaly-related early childhood mortality in the United States between 1999 and 2020: A nationwide CDC WONDER analysis

Anencephaly is a severe neural tube defect that affects approximately 1 in every 5250 live births in the United States. This fatal congenital condition is linked to modifiable risk factors, including folic acid deficiency, maternal diabetes, and exposure to teratogenic medications such as certain anti-epileptics. Despite public health efforts to promote folic acid supplementation, disparities in mortality persist. This study aimed to evaluate national trends in anencephaly-related early childhood mortality from 1999 to 2020 using the CDC Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) database. We analyzed death certificate data from the CDC WONDER system to assess trends in anencephaly-related mortality among children from birth to 4 years of age between 1999 and 2020. Age-adjusted mortality rates (AAMRs) per 100,000 population and annual percent changes (APCs) with 95% confidence intervals (CIs) were calculated. Mortality trends were stratified by sex, race/ethnicity, U.S. Census region, state, and 2013 urbanization classification. Between 1999 and 2020, there were 6969 anencephaly-related early childhood deaths in the United States, with 89.7% occurring in medical facilities. The overall AAMR declined from 1.7 in 1999 to 1.5 in 2020 (APC: -0.43; 95% CI: -0.94 to 0.09), with peaks in 2000 and 2012 (AAMR: 1.8). Females consistently had higher AAMRs than males (1.8 vs 1.4). By race, Hispanic individuals had the highest AAMR (2.0), followed by NH White (1.7) and NH Black (1.2), with significant declines among Hispanic and NH Black population. Regionally, the highest AAMR was in the Midwest (1.9), and the lowest in the Northeast (1.0). Among states, South Dakota had the highest (3.2), and Connecticut the lowest (0.5). Noncore metropolitan areas exhibited the highest AAMR (2.1), with varying temporal trends across urbanization levels. Anencephaly-related early childhood mortality has declined in the United States from 1999 to 2020; however, disparities remain. Higher mortality rates persist among Hispanic/Latino populations and in nonmetropolitan areas, highlighting the need for targeted public health interventions. These findings underscore the importance of expanding access to folic acid supplementation, culturally tailored maternal health education, and equitable prenatal care services, especially in underserved communities.