Epidemiology of Neural Tube Defects in Puerto Rico in the Era of Folic Acid Fortification: Population-Based Surveillance, Pregnancy Outcomes, and Lesion Patterns (2015-2024).

BACKGROUND: Neural tube defects (NTDs) remain clinically important congenital conditions, but contemporary Puerto Rico-specific epidemiological data in the current folic acid fortification era are limited. OBJECTIVES: To describe the epidemiology of NTDs in Puerto Rico from 2015 through 2024, characterize pregnancy outcomes and lesion patterns, evaluate temporal trends, and compare contemporary metrics with prior Puerto Rico reports using directly comparable denominators. METHODS: Retrospective population-based cross-sectional surveillance study of NTD-affected pregnancies in Puerto Rico, 2015-2024. Case data were obtained from the Puerto Rico NTD surveillance dataset; annual live-birth denominators were obtained from the Puerto Rico Department of Health. Surveillance-based rates per 10,000 live births were calculated with exact Poisson 95% confidence intervals. Temporal trends were evaluated with negative binomial regression. The study was conducted under local institutional and public health data policies as a secondary analysis of de-identified data; institutional review board review was not required. RESULTS: Among 194 NTD-affected pregnancies and 220,138 live births, the overall surveillance-based rate was 8.8 per 10,000 live births (95% CI 7.6, 10.1). No significant temporal trend was identified (rate ratio 1.01, 95% CI 0.81, 1.26). The live-born NTD rate was 3.7 per 10,000 live births (95% CI 3.0, 4.6). Spina bifida (88; 45.4%) and anencephaly (79; 40.7%) predominated. Termination occurred in 54 of 79 (68.4%) anencephaly pregnancies compared with 23 of 88 (26.1%) spina bifida pregnancies. Lumbosacral lesions were the most common spina bifida level (39; 44.3%). CONCLUSIONS: The contemporary live-born NTD rate in Puerto Rico is lower than the pre-fortification era estimate, reflecting the influence of prenatal diagnosis and termination. The overall surveillance-based rate remains similar to the earlier post-fortification estimate, with no significant recent decline, supporting the need for strengthened territory-specific surveillance and earlier, coordinated folate-centred prevention strategies.