title: The enigma of preterm birth.
mesh_terms: D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D007752:Obstetric Labor, Premature / Q000453:epidemiology / Q000209:etiology*; D011247:Pregnancy; D012307:Risk Factors; D012959:Socioeconomic Factors