Maternal intake of fat, riboflavin and nicotinamide and the risk of having offspring with congenital heart defects.

BACKGROUND With the exception of studies on folic acid, little evidence is available concerning other nutrients in the pathogenesis of congenital heart defects (CHDs). Fatty acids play a central role in embryonic development, and the B-vitamins riboflavin and nicotinamide are co-enzymes in lipid metabolism. AIM OF THE STUDY To investigate associations between the maternal dietary intake of fats, riboflavin and nicotinamide, and CHD risk in the offspring. METHODS A case-control family study was conducted in 276 mothers of a child with a CHD comprising of 190 outflow tract defects (OTD) and 86 non-outflow tract defects (non-OTD) and 324 control mothers of a non-malformed child. Mothers filled out general and food frequency questionnaires at 16 months after the index-pregnancy, as a proxy of the habitual food intake in the preconception period. Nutrient intakes (medians) were compared between cases and controls by Mann-Whitney U test. Odds ratios (OR) for the association between CHDs and nutrient intakes were estimated in a logistic regression model. RESULTS Case mothers, in particular mothers of a child with OTD, had higher dietary intakes of saturated fat, 30.9 vs. 29.8 g/d; P < 0.05. Dietary intakes of riboflavin and nicotinamide were lower in mothers of a child with an OTD than in controls (1.32 vs. 1.41 mg/d; P < 0.05 and 14.6 vs. 15.1 mg/d; P < 0.05, respectively). Energy, unsaturated fat, cholesterol and folate intakes were comparable between the groups. Low dietary intakes of both riboflavin (<1.20 mg/d) and nicotinamide (<13.5 mg/d) increased more than two-fold the risk of a child with an OTD, especially in mothers who did not use vitamin supplements in the periconceptional period (OR 2.4, 95%CI 1.4-4.0). Increasing intakes of nicotinamide (OR 0.8, 95%CI 0.7-1.001, per unit standard deviation increase) decreased CHD risk independent of dietary folate intake. CONCLUSIONS A maternal diet high in saturated fats and low in riboflavin and nicotinamide seems to contribute to CHD risk, in particular OTDs.