Prevalence of neural tube defects and estimation of cases averted in the post-fortification period in Argentina

Abstract

Periconceptional intake of folic acid has demonstrated to be effective to reduce the frequency of neural tube defects, and food fortification has been one of the strategies implemented to increase it. An update is herein presented on the reduced prevalence of neural tube defect cases in the post-fortification period in Argentina and an estimation of cases averted in the 2005-2013 period as a result of this intervention. When comparing the prevalence observed in the post-fortification period to that reported in the pre-fortification period, anencephaly and encephalocele decreased by 66%, and spina bifida, by 47%, which were significant reductions. The estimated number of cases averted was higher for anencephaly, followed by spina bifida; encephalocele showed the lowest number of cases averted given that the prevalence of this defect was smaller. The decrease observed in the prevalence supports findings from previous studies on the impact of fortification.

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

“…However, comparisons between sources should be made with caution considering the period covered by each source and, as will be discussed below, the numerator to which they are referred. The observed periods are different from previous precedents on NTD epidemiology and generally shorter (Bidondo et al, 2015; Bronberg et al, 2011; Calvo & Biglieri, 2008; López‐Camelo et al, 2010). After the sharp drop in fetal deaths during the immediate post‐fortification period between 2003 and 2006, the prevalence of NTDs, particularly anencephaly, continues to decline monotonically, representing only 9.4% of fetal congenital malformations in 2009 in contrast with the 34.7% prevalence it presented in 1994.…”

“…In relation to folic acid fortification, we observe, as in infant deaths (Bronberg et al, 2011; Calvo & Biglieri, 2008) and in newborns (Bidondo et al, 2015; López‐Camelo et al, 2010), a statistically significant negative secular trend after fortification, but of greater magnitude with respect to infant deaths (53% vs. 66%). However, comparisons between sources should be made with caution considering the period covered by each source and, as will be discussed below, the numerator to which they are referred.…”

“…However, comparisons between sources should be made with caution considering the period covered by each source and, as will be discussed below, the numerator to which they are referred. The observed periods are different from previous precedents on NTD epidemiology and generally shorter (Bidondo et al, 2015;Bronberg et al, 2011;Calvo & Biglieri, 2008; L opez-Camelo T A B L E 1 Fetal deaths from anencephaly, myelomeningocele, neural tube defects, congenital malformations, and live newborns in Argentina during the period 1994-2019. When considering the rate of anencephaly*10,000 live newborns, the difference between the beginning and the end of the period is 17%.…”

“…Based on the death certificates of children less than 1 year of age for the period 1998–2007 in Argentina, Bronberg et al (2011) estimate a 53% reduction in mortality risk due to anencephaly at the national level after fortification, with regional variations. Based on data from the ECLAMC (Latin American Collaborative Study of Congenital Malformations) concerning to Argentina and the National Registry of Congenital Anomalies (RENAC), Bidondo et al (2015) compared the prevalence observed in live births during the post‐fortification period with that reported in the pre‐fortification period (López‐Camelo et al, 2010) and observed a significant decrease of 66% for anencephaly and encephalocele and 47% for spina bifida.…”