Prevalence and secular trend of neural tube defects in fetal deaths in Argentina, 1994–2019

Abstract

Background: Fetal deaths are a major source of information on the epidemiology of neural tube defects (NTDs; anencephaly and myelomeningocele). We analyzed NTDs prevalence and secular trend using fetal death records between 1994 and 2019 in Argentina. Materials and Methods: Data were obtained from the Department of Statistics and Information of the Ministry of Health (DEIS). Using the number of fetal deaths due to anencephaly and myelomeningocele, we estimated the proportion of all fetal deaths due to anencephaly, myelomeningocele, and NTDs (anencephaly + myelomeningocele) during pre- and post-fortification period in Argentina. We also estimated the ratio of fetal deaths due to anencephaly, myelomeningocele, and NTDs (anencephaly + myelomeningocele) to 10,000 live births. Secular trend in the outcomes was analyzed using a Poisson model and Joinpoint regression analysis. Results: In the entire period analyzed, the NTD proportion on fetal deaths was 1.32. In 1994, NTDs accounted for 34.7% of congenital malformations fetal deaths (CM) and 1.7% of all fetal deaths, whereas in 2019, these percentages were 9.4% and 0.5%, respectively. NTDs present a negative secular trend (p <.05). The risk of fetal death due to anencephaly and myelomeningocele decreases between 2005 and 2019 by 67% and 51% respectively (p <.05) in comparison to the period between 1994 and 2004 before the effective fortification of wheat flour used in the food industry destined for the domestic market. Discussion and Conclusion: We found a significant decrease in the risk of all fetal deaths due to NTDs, particularly anencephaly, in Argentina over the study period, with most reduction observed during the mandatory flour fortification era (introduced in Argentina in 2002). The inclusion of fetal deaths in NTD surveillance, coupled or uncoupled with other pregnancy outcomes, is essential for monitoring preventive supplementation measures.