A study of risks, medical care, and infant mortality. 4. Methodological considerations.
D001034:Apgar Score; D001719:Birth Certificates; D001724:Birth Weight; D000013:Congenital Abnormalities / Q000453:epidemiology; D003644:Death Certificates; D003710:Demography; D004219:District of Columbia; D004522:Educational Status; D005260:Female; D005865:Gestational Age; D006761:Hospitals; D006801:Humans; D007086:Illegitimacy; D007226:Infant Mortality; D007231:Infant, Newborn; D008423:Maternal Age; D008499:Medical Records; D008722:Methods; D009518:New York; D010290:Parents; D011247:Pregnancy; D011248:Pregnancy Complications; D011295:Prenatal Care; D012959:Socioeconomic Factors; D013514:Surgical Procedures, Operative