Fifty-five fetuses with a pre-termination diagnosis of neural tube defect or hydrocephalus were examined. Termination was carried out on the basis of an elevated amniotic alpha-fetoprotein in 24 and on ultrasound examination in 31. Although pre-termination diagnosis was confirmed in 45 cases, a new or more refined diagnosis was made in 10. There was a high incidence of non-neural tube malformations. Fetuses terminated in a prenatal diagnosis screening programme should always be examined to establish the exact diagnosis for the provision of recurrence risks for genetic counselling and as a quality control for the test involved.