title: Social factors in the incidence of spinal bifida and anencephaly.
mesh_terms: D000757:Anencephaly / Q000453:epidemiology* / Q000235:genetics; D001722:Birth Order; D003267:Contraception; D005260:Female; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D012959:Socioeconomic Factors; D016135:Spinal Dysraphism / Q000453:epidemiology* / Q000235:genetics; D006113:United Kingdom