The tiniest newborns.
D004992:Ethics, Medical; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D007363:Intensive Care Units, Neonatal / Q000191:economics*; D008297:Male; D028681:Moral Obligations; D018579:Patient Selection; D040841:Resource Allocation; D012959:Socioeconomic Factors; D014481:United States; D028761:Withholding Treatment