title: Seasonal variation in the frequency of anencephalus and spina bifida births in the United Kingdom.
abstract: There have been statistically significant seasonal variations of annencephalus and spina bifida in each country of the United Kingdom during 1964-79 with the exception of anencephalus births in Northern Ireland. The seasonal peaks, where discernible, are in phase. Embryos appear to develop anencephalus most commonly in May-June and spina bifida in July.
mesh_terms: D000757:Anencephaly / Q000453:epidemiology*; D004739:England; D006801:Humans; D007231:Infant, Newborn; D009660:Northern Ireland; D012606:Scotland; D012621:Seasons; D016136:Spina Bifida Occulta / Q000453:epidemiology*; D014852:Wales