title: One-carbon metabolite levels in mid-pregnancy and risks of conotruncal heart defects.
abstract: 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.
  
  
  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.
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, California.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Shaw
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Suzan L
authors.initials: SL
authors.lastname: Carmichael
authors.forename: Stein Emil
authors.initials: SE
authors.lastname: Vollset
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Hobbs
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Lammer
authors.forename: Per M
authors.initials: PM
authors.lastname: Ueland
mesh_terms: D000328:Adult; D018070:Biological Specimen Banks; D002140:California; D016022:Case-Control Studies; D005260:Female; D006330:Heart Defects, Congenital / Q000097:blood* / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007231:Infant, Newborn; D055442:Metabolome; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000097:blood*; D011446:Prospective Studies; D012307:Risk Factors
keywords: B vitamins; folic acid; heart defects; nutrition; pregnancy