title: Background and methodology of a study of congenital malformations.
mesh_terms: D001719:Birth Certificates; D000013:Congenital Abnormalities / Q000453:epidemiology*; D003644:Death Certificates; D005260:Female; D005313:Fetal Death; D006761:Hospitals; D006801:Humans; D007231:Infant, Newborn; D007484:Iowa; D008499:Medical Records; D011247:Pregnancy