Birth weight and Legg-Perthes disease.
D001699:Biometry; D001722:Birth Order; D001724:Birth Weight; D002648:Child; D002675:Child, Preschool; D005260:Female; D006306:Health Surveys; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008404:Massachusetts; D010007:Osteochondritis / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D012189:Retrospective Studies; D012907:Smoking