Multiple pregnancy: the value of twins in genetic studies.
D000013:Congenital Abnormalities / Q000453:epidemiology; D004200:Diseases in Twins / Q000453:epidemiology; D005260:Female; D005826:Genetics, Medical; D006801:Humans; D008297:Male; D011247:Pregnancy; D011272:Pregnancy, Multiple; D012106:Research; D014427:Twins