Spina bifida and neural tube defects

Abstract

It has been established that the incidence of anencephaly is higher in Ireland than in other Western European countries. The incidence of neural tube defect, however, is less precisely documented. Penrose (1957) noted that a high incidence of anencephaly is usually matched by a similary high incidence of spina bifida but that the Irish incidence of anencephaly was not matched by a correspondingly high incidence of spina bifida. Findings in this study do not support the latter view. 305 infants with neural tube malformations presented at birth over the twelve-year period, giving an incidence of 3.9 per 1,000 births. A high proportion (22%) were stillborn. In 66% of the cases, a meningo-myelocoele was present. Mothers under twenty years were at a significantly higher risk and there was a highly significant excess of female infants. A significant reduction in the period 1975-1977, as compared with the previous nine years, was noted.