Disparities in Surveillance of Neural Tube Defects Across WHO Regions and World Bank Income Levels

Introduction: Neural tube defects (NTD) are an important and often preventable cause of morbidity and mortality worldwide. Well-planned global neurosurgery and public health efforts can aid vulnerable communities, but there is a need to elucidate the global burden of NTDs and identify regions without available data to better target interventions.

Methods: We conducted a scoping review to quantify worldwide NTD prevalence using the PubMed/Medline and birth defects surveillance registries. Data published after January 1st, 1990 that encompassed prevalence values of at least the two most prevalent NTDs - spina bifida and encephalocele- was abstracted. Mean NTD prevalence rates were aggregated by WHO region and World Bank classification of the study country and differences were determined using the ANOVA test. Differences in the availability of nationally representative data by WHO region and World Bank classification were determined using chi-square tests.

Results: The percentage of countries within each region with available NTD prevalence data was highest in the Eastern Mediterranean Region (18/21; 85.7%) and lowest in the Africa Region (15/48; 31.3%). The global range of NTD prevalence rates was 0.9 – 269.6 per 10,000 births. There was a statistically significant difference in reported NTD prevalence rates depending on the WHO Region (p= 0.00027) and World Bank Income Level of the study country (p= 0.00193). Forty countries (43%) had conducted national-level studies to assess NTD prevalence. There was a statistically significant difference in the data quality availability of nationally representative data depending on the WHO region (p= 0.0081) and World Bank classification of study country (p= 0.0017).

Conclusion : There is a gap in the availability of NTD prevalence data worldwide, with the majority of WHO member states lacking any NTD prevalence estimates, especially national-level studies. These findings highlight the need for greater NTD surveillance efforts and identify the countries with the greatest need for targeted global intervention.