Anencephalus: a changing sex ratio.
D000757:Anencephaly / Q000453:epidemiology*; D004739:England; D005163:Factor Analysis, Statistical; D005260:Female; D005313:Fetal Death / Q000453:epidemiology; D006801:Humans; D006849:Hydrocephalus / Q000453:epidemiology; D007231:Infant, Newborn; D008297:Male; D009660:Northern Ireland; D011247:Pregnancy; D012606:Scotland; D012737:Sex Factors; D014852:Wales