[Type and incidence of abnormalities in 23,939 newborn infants in a 5-year period].

23,939 children born consecutively at the Department of Obstetrics and Gynaecology, University of Graz, over a 5-year period ending 31. 12. 1984 were surveyed for the presence of major malformations. 394 (1.6%) had a major congenital defect. Within the same time 392 infants died during the perinatal period, 86 of them being malformed (22%). The malformations were listed according the most likely mode of inheritance, revealing a total of 80 different congenital defects. About 70% of these malformations are associated with an increased recurrence risk (greater than 1%) and 15% carry a high risk of recurrence (greater than 10%). These facts point to the importance of prenatal diagnosis and proper genetic counselling.