1. From the Section for Epidemiology and Medical Statistics, Department of Public Health and Primary Health Care (RMN, SEV, and HKG), and the LOCUS for Homocysteine and Related Vitamins and the Section for Pharmacology, Institute of Medicine (PMU), University of Bergen, Bergen, Norway; the Medical Birth Registry, Norwegian Institute of Public Health, Bergen, Norway (SEV); and the Divisions of Epidem