title: Congenital malformations: the contribution of twin studies.
mesh_terms: D000013:Congenital Abnormalities / Q000235:genetics*; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D044469:Racial Groups; D012042:Registries; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic