Estimates of global and regional prevalence of neural tube defects for 2015: a systematic analysis

Abstract

Neural tube defects (NTDs) are associated with substantial mortality, morbidity, disability, and psychological and economic costs. Many are preventable with folic acid, and access to appropriate services for those affected can improve survival and quality of life. We used a compartmental model to estimate global and regional birth prevalence of NTDs (live births, stillbirths, and elective terminations of pregnancy) and subsequent under-5 mortality. Data were identified through web-based reviews of birth defect registry databases and systematic literature reviews. Meta-analyses were undertaken where appropriate. For 2015, our model estimated 260,100 (uncertainty interval (UI): 213,800-322,000) NTD-affected birth outcomes worldwide (prevalence 18.6 (15.3-23.0)/10,000 live births). Approximately 50% of cases were elective terminations of pregnancy for fetal anomalies (UI: 59,300 (47,900-74,500)) or stillbirths (57,800 (UI: 35,000-88,600)). Of NTD-affected live births, 117,900 (ß75%) (UI: 105,500-186,600) resulted in under-5 deaths. Our systematic review showed a paucity of high-quality data in the regions of the world with the highest burden. Despite knowledge about prevention, NTDs remain highly prevalent worldwide. Lack of surveillance and incomplete ascertainment of affected pregnancies make NTDs invisible to policy makers. Improved surveillance of all adverse outcomes is needed to improve the robustness of total NTD prevalence estimation, evaluate effectiveness of prevention through folic acid fortification, and improve outcomes through care and rehabilitation.

Improving maternal folate status to prevent infant neural tube defects: working group conclusions and a framework for action

“…A complementary report on this section focused on estimating the global and regional prevalence of NTDs for the year 2015 using updated information from birth defects registries and current literature. The authors estimate that 260,100 NTD‐affected pregnancies occurred in 195 countries (uncertainty interval 213,800–322,000), reflecting a prevalence of 1.86 (1.53–2.30) per 1000 live births, resulting in 117,900 (81,100–148,500) under‐five deaths and 57,800 (35,000–88,600) stillbirths …”

“…The committee strongly endorsed the need to obtain better information on folate status of WRA, which will require the use of appropriate laboratory methods to assess folate status and correct interpretation of the data to help support NTD prevention efforts. The new estimations for global NTD prevalence for 195 countries for the year 2015 provide a needed update on this figure and underscore the magnitude of the problem, calling for a more dedicated effort to prevent these conditions.…”

Historical perspective on folic acid and challenges in estimating global prevalence of neural tube defects

“…Recently, Blencowe et al . extended the Modell methodology and estimated 260,100 NTD‐affected pregnancies worldwide in 2015, of which approximately 50% were electively terminated . Over 75% of NTD‐affected births resulted in death by 5 years of age .…”

“…extended the Modell methodology and estimated 260,100 NTD‐affected pregnancies worldwide in 2015, of which approximately 50% were electively terminated . Over 75% of NTD‐affected births resulted in death by 5 years of age . The global prevalence of NTD was estimated by Blencowe and colleagues to be 1.86 per 1000 live births in 2015, while varying in different regions of the world between 0.75 and 3.12 per 1000 live births …”

“…Over 75% of NTD‐affected births resulted in death by 5 years of age . The global prevalence of NTD was estimated by Blencowe and colleagues to be 1.86 per 1000 live births in 2015, while varying in different regions of the world between 0.75 and 3.12 per 1000 live births …”