Obstetric aspects of preterm delivery.
D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D008396:Maryland; D007752:Obstetric Labor, Premature / Q000453:epidemiology*; D011247:Pregnancy; D009626:Terminology as Topic; D014944:World Health Organization