Anencephaly and potato blight in the Republic of Ireland.

National potato tuber blight scores in the Republic of Ireland for the years 1961-70 were ascertained and evaluated in relation to incidence of anencephalic births in the following years. No significant relationship between annual tuber blight scores and incidence of anencephaly one year later could be demonstrated. Examination of the records of a maternity hospital for the years before, during, and after the great midnineteenth century potato famine in Ireland failed to show any appreciable fluctuation in anencephaly/spina bifida incidence during this period.