Regionalization revisited.
D002662:Child Health Services / Q000458:organization & administration*; D005260:Female; D006761:Hospitals / Q000145:classification; D006801:Humans; D007231:Infant, Newborn; D008427:Maternal Health Services / Q000458:organization & administration*; D011247:Pregnancy; D012041:Regional Medical Programs / Q000458:organization & administration*; D014481:United States