Spina bifida and anencephalus in greater London.
D000293:Adolescent; D000328:Adult; D000757:Anencephaly / Q000453:epidemiology* / Q000235:genetics; D001722:Birth Order; D001723:Birth Rate; D002648:Child; D002675:Child, Preschool; D003241:Consanguinity; D004200:Diseases in Twins; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008131:London; D008297:Male; D008423:Maternal Age; D008875:Middle Aged; D012111:Residence Characteristics; D012621:Seasons; D012923:Social Class; D016135:Spinal Dysraphism / Q000453:epidemiology* / Q000235:genetics