The work included 35 patients having single primary structural defects of prenatal onset. Their ages ranged from 1 week to 2.5 years. The study was conducted over a period of three months to children admitted to a word in Cairo University Children's hospital. Children with multiple malformations were not included in the study. 12 cases (34.3%) had cardiovascular abnormalities. Gastrointestinal abnormalities were found in 8 cases (22.9%), 8 cases (22.9%) had limb abnormalities, 4 cases (11.4%) had urogenital abnormalities and 2 cases (5.7%) had central nervous system abnormalities. while 1 case (2.8%) had eye abnormalities. A family history of positive consanguinity in 16 (45.7%) cases, 7 cases (20%) and 10 (28.6%) cases had a maternal history of disease or drug intake during pregnancy respectively.