reduced during the first six months by non-closure of the defect. Presumably non-closure allows cerebrospinal fluid to escape from the open neural tube, postponing the development of hydrocephalus until epithelium has formed. As deferred shunt operations are associated with a better prognosis,4 nonclosure may in fact be advantageous, delaying the onset of ventriculitis until the child is immunologically more competent.Thus early closure has no advantage over non-closure with respect to mortality and the incidence of hydrocephalus and ventriculitis. Non