This study will examine how the body metabolizes micronutrients, such vitamins, during pregnancy and how genetic make-up influences their metabolism. Vitamin B12 and folate levels in pregnancy have been linked to birth defects, such as neural tube defects, orofacial clefts, and congenital heart disease. Other micronutrient levels may be related to other birth defects or pregnancy complications. This study will characterize the patterns of micronutrient status during pregnancy and compare it with genetic variants and biochemical parameters. Information about the relationship between genes and vitamin metabolism may help doctors advise women about their nutritional requirements during pregnancy to protect their health and the health of their babies.

This study is a collaboration between NIH and Trinity College in Dublin, Ireland. Women of Irish origin 18 years of age or older who are receiving prenatal care at the Coombe Women's Hospital in Dublin may be enrolled. Fathers also may participate.

Upon entering the study, female participants complete a questionnaire relating to their food and vitamin intake, alcohol consumption, smoking behavior, and use of medications, and provide a blood sample. Additional blood samples are collected during routine clinic visits at about 24 and 34 weeks of pregnancy, and again at delivery and from 6 weeks to 2 months after the baby's birth. Permission will be requested to obtain a blood sample from the umbilical cord at birth after it has been removed from the baby.

Fathers of the babies are also asked to answer a short questionnaire and to provide a DNA sample for genetic studies. To collect the DNA, sterile cotton swabs are rubbed around the inside of the mouth to obtain cheek cells from which the DNA is extracted.