Some aspects of triplet pregnancies in England and Wales, 1971--1975.
D004739:England; D005260:Female; D005313:Fetal Death / Q000453:epidemiology; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D011272:Pregnancy, Multiple; D012737:Sex Factors; D014310:Triplets; D014852:Wales