One-Carbon Metabolite Levels in Mid-Pregnancy and Risks of Conotruncal Heart Defects

BACKGROUND:Evidence exists for an association between use of vitamin supplements with folic acid in early pregnancy and reduced risk for offspring with conotruncal heart defects. A few observations have been made about nutrients related to one-carbon metabolism other than folate. Our prospective study attempted to extend information on nutrition and conotruncal heart defects by measuring analytes in mid-pregnancy sera.METHODS:This study included data from a repository of women's mid-pregnancy serum specimens based on screened pregnancies in California from 2002-2007. Each woman's specimen was linked with delivery information to determine whether her fetus had a conotruncal heart defect or another structural malformation, or was nonmalformed. We identified 140 conotruncal cases and randomly selected 280 specimens as nonmalformed controls. Specimens were tested for a variety of analytes, including homocysteine, methylmalonic acid, folate, vitamin B12 , pyridoxal phosphate, pyridoxal, pyridoxic acid, riboflavin, total choline, betaine, methionine, cysteine, cystathionine, arginine, asymmetric and symmetric dimethylarginine.RESULTS AND CONCLUSIONS:We did not observe statistical evidence for substantial differences between cases and controls for any of the measured analytes. Analyses specifically targeting B-vitamins also did not reveal differences between cases and controls.