# A Population-Based Study of U.S. Trends in Selected Congenital Anomalies (2016–2023) and Socio-Demographic Disparities: A CDC WONDER Analysis

## TL;DR

The study found that 3.3 out of every 1000 U.S. live births in 2023 had selected birth defects, with higher risks among certain maternal and infant groups.

## Contribution

This study provides updated national data on congenital anomalies and socio-demographic disparities in the U.S. from 2016 to 2023.

## Key findings

- The overall prevalence of selected congenital anomalies was 3.3 per 1000 live births in 2023.
- American Indian/Alaska Native infants had higher risk compared to other racial groups.
- A modest decline in overall prevalence was observed from 2016 to 2023.

## Abstract

What are the main findings?
Overall prevalence of selected congenital anomalies was 3.3 per 1000 live births in 2023.Higher risk was observed with pre-pregnancy diabetes, advanced maternal age, tobacco use, and higher BMI and among American Indian/Alaska Native infants.

Overall prevalence of selected congenital anomalies was 3.3 per 1000 live births in 2023.

Higher risk was observed with pre-pregnancy diabetes, advanced maternal age, tobacco use, and higher BMI and among American Indian/Alaska Native infants.

What are the implications of the main findings?
Targeted preconception and early prenatal interventions may reduce modifiable risks and address disparities.Continued national surveillance can inform policy and resource allocation for prevention and care.

Targeted preconception and early prenatal interventions may reduce modifiable risks and address disparities.

Continued national surveillance can inform policy and resource allocation for prevention and care.

Background: Congenital anomalies are influenced by genetic and environmental factors. While interventions including folic acid supplementation have reduced neural tube defects, data on modifiable socio-demographic risk factors remain limited. Aim: This study aimed to assess variation in the prevalence of selected congenital anomalies across the United States according to socio-demographic factors. Methods: A population-based analysis was conducted using CDC-WONDER natality data from 2016 to 2023. Included anomalies were anencephaly, spina bifida, cyanotic heart disease, diaphragmatic hernia, omphalocele, gastroschisis, limb reduction, cleft lip/palate, Down syndrome, chromosomal disorders, and hypospadias. Associations with maternal age, BMI, race, tobacco use, diabetes, and fertility treatments were analyzed. Prevalence rates were calculated per 1000 live births. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated. Joinpoint regression was used to assess annual percent changes (APCs), with p < 0.05 considered significant. Results: Among 3,482,944 singleton live births in 2023, the overall prevalence of the selected congenital anomalies was 3.3 per 1000. Compared to Caucasian mothers, risk was lower in Asian (RR 0.57; 95% CI: 0.52–0.63) and Black (RR 0.81; 95% CI: 0.76–0.85) infants and higher in American Indian/Alaska Native infants. Significant risk factors included pre-pregnancy diabetes (RR 2.41; 95% CI: 2.16–2.69), maternal age > 45 (RR 2.95; 95% CI: 2.36–3.69), and tobacco use (RR 1.78; 95% CI: 1.64–1.94). A significant decline in prevalence was observed from 2016 to 2023 (APC: −0.6%; 95% CI: −1.1 to −0.2; p = 0.006). Conclusions: Significant disparities and modifiable maternal risk factors were associated with the prevalence of selected congenital anomalies in the U.S. from 2016 to 2023. A modest statistically significant decline in overall prevalence was observed during the study period, supporting the importance of continued national surveillance and targeted preconception and prenatal interventions to reduce risk and address inequities.