title: Twins--still a perinatal problem.
mesh_terms: D004200:Diseases in Twins / Q000401:mortality; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000401:mortality*; D011247:Pregnancy; D011272:Pregnancy, Multiple; D014427:Twins