Archief Roodbont

Fall in congenital heart defects after folic acid fortification introduced

19 May 2009

MedWire News: The birth prevalence of severe congenital heart defects in Canada fell significantly after the introduction of a public health measure to fortify grain with folic acid, a study shows.

The findings support the hypothesis that folic acid has a preventive effect on heart defects, say the authors.

Louise Pilote (McGill University, Montreal, Canada) and colleagues analyzed Quebec administrative databases to establish the annual birth prevalence of severe congenital heart defects (tetralogy of Fallot, endocardial cushion defects, univentricular hearts, truncus arteriosus, or transposition complexes) in the period 1990 to 2005.

Fortification of grain products has been mandatory in Canada since December 1998, the researchers explain, but the impact on birth heart defects at the population level has not previously been examined.

Writing in an advance online publication by the British Medical Journal, they report that 2083 infants were born with severe congenital heart defects out of a total of 1,324,440 births during the whole study period. This corresponded to an average birth prevalence of 1.57 per 1000 births.

Time trend analysis showed that there was no change in the birth prevalence of congenital heart defects in the 9 years before folic acid fortification, at a rate ratio of 1.008. But the 7-year period after the introduction of mandatory fortification of flour and pasta with folic acid was accompanied by a 6.2% decrease per year in birth prevalence, at a rate ratio of 0.938.

Further analysis showed a significant (p<0.001) interaction between the time period (before/after fortification) and calendar year, “suggesting that the decreasing trend after the flour fortification did not occur by chance,” Pilote and co-authors note.

The change in time trend was seen for both conotruncal and non-conotruncal defects analyzed separately.

The researchers conclude that future studies are needed to address the impact of folic acid fortification on the incidence of congenital heart defects and its long-term effects, as well as to determine the optimal level of folic acid intake required to achieve a reduction in the birth prevalence.

MedWire is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009

Br Med J 2009; Advance online publication