This study is designed as a prospective cohort study of women referred for fetal echocardiography. In 14 percent of women who undergo this test, a congenital heart defect, particularly a conotruncal defect or a ventricular septal defect (VSD), will be diagnosed in utero A cohort will be formed from all women who consent to this protocol and undergo fetal echocardiography (referral cohort). A second control cohort will be chosen as consecutive women seen in the prenatal clinics at OHSU with normal pregnancies who do not undergo fetal echocardiography. Prior to the fetal echocardiogram in the referral cohort, and at 16 to 26 weeks of gestation in the cohort recruited from the prenatal clinics, each women will be questioned to collect information about basic demographic factors, lifestyle maternal and fetal risk factors, and intake of specific foods using the Block food frequency questionnaire. A blood sample will be drawn from all women and stored at -80C. Plasma folate and B12,, RBC folate, and homocysteine will be analyzed as a nested case-control study in blood samples from all mothers of offspring with conotruncal defects or ventricular septal defects, and from three controls from each control cohort matched to the case on the date of the blood draw and gestational age. All children with conotruncal defects or isolated VSD will have a chromosomal analysis for 22q11 deletion. The outcome of a diagnosed conotruncal defect or VSD will be determined by a pediatric cardiologist, combining fetal echocardiography, postnatal echocardiography, and clinical assessment. This protocol will determine if low folate or vitamin B12 intakes or abnormal folate metabolism is related t the occurrence of congenital heart defects,
