Spina bifida folate fortification in Brazil, update 2022: a cross-sectional study

Area of Science:

• Public Health
• Epidemiology
• Nutritional Science

Background:

• Congenital malformations remain a significant cause of mortality in early childhood in Brazil.
• Flour fortification with folic acid (FA) is a public health strategy to reduce neural tube defects.
• Understanding the impact of FA fortification on spina bifida (SB) rates is crucial for maternal and child health.

Purpose of the Study:

• To compare spina bifida (SB) prevalence rates in Brazil before and after the implementation of folic acid (FA) fortification in flour.
• To evaluate the statistical significance of changes in SB rates following different phases of FA fortification (maize/wheat and cassava flour).

Main Methods:

• A cross-sectional, population-based study utilizing data from Brazil's Live Birth Information System (SINASC/SUS).
• Comparison of SB rates between pre-fortification (1999-2004) and post-fortification periods (2005-2010 and 2011-2020).
• Statistical analysis using prevalence ratio (PRR) with 95% confidence intervals and a random effects model.

Main Results:

• A non-statistically significant tendency towards decreased PRR was observed after maize and wheat flour fortification (Rate Ratio = 1.05, p=0.075).
• A statistically significant increase in SB rates was observed after cassava flour fortification (Rate Ratio = 1.4, p<0.01).
• The study indicates a potential rise in SB prevalence following folic acid fortification initiatives.

Conclusions:

• The study found an increase in SB rates post-folic acid fortification, contrary to expected outcomes.
• Potential explanations include improvements in national registry accuracy, inadequate staple food fortification, or unidentified factors.
• Recommendations include mandatory malformation registries, inspection of FA concentrations in flour, and universal food fortification.