Significance of a single umbilical artery: Report from the collaborative study of cerebral palsy

Abstract

1.1. A total of 26,539 placentas of single births obtained from 12 different institutions enrolled in the collaborative study were evaluated, in which 203 (0.76 per cent) showed a single umbilical artery on gross and microscopic examination.2.2. The incidence of single umbilical artery in the white was 1.22 per cent, a higher incidence than in the Negro, which was 0.44 per cent. This racial difference was consistently present in the various institutes and in all maternal age and birth weight groups. Conversely, the incidence of associated congenital malformations was higher in the Negro (42.1 per cent) than in the white (23.0 per cent).3.3. Associated congenital malformations were classified into three Types of malformations: A (lethal or major), B (nonlethal), and C (borderline). The over-all incidence of associated malformations (Types A, B, plus C) was 28.6 per cent. When the Type C malformations were excluded, the incidence was 16.7 per cent. Type A malformations were found in 9 of the 20 stillbirths and in 4 of the 6 neonatal deaths, but only in 7 (4.0 per cent) of the 174 survivors. Skeletal system anomalies showed the highest incidence in the associated malformations.4.4. The incidence of SUA was 1.98 per cent in infants of low birth weight (2,500 grams and under). In infants weighing over 2,500 grams the incidence was 0.63 per cent.5.5. Maternal diabetes was 6.4 per cent, an incidence 5 times higher than in the control group.