Epidemiology of anencephalus, spina bifida, and congenital hydrocephalus.
D000757:Anencephaly / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000453:epidemiology*; D008297:Male; D016135:Spinal Dysraphism / Q000453:epidemiology*; D006113:United Kingdom