Twin pregnancy and erythroblastosis.
D000017:ABO Blood-Group System; D003298:Coombs Test; D004200:Diseases in Twins; D004899:Erythroblastosis, Fetal / Q000453:epidemiology / Q000276:immunology; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007751:Labor, Induced; D007752:Obstetric Labor, Premature; D011247:Pregnancy; D012204:Rh-Hr Blood-Group System
D000017:ABO Blood-Group System; D012204:Rh-Hr Blood-Group System