Congenital renal agenesis: case-control analysis of birth characteristics.

Renal agenesis (RA) is the most common congenital urinary malformation; however, evidence for prenatal factors associated with the development of this condition is limited. The aim of this study is to determine prenatal and perinatal factors associated with the development of RA. We performed a case-control study of Colorado births with RA from 1989 to 1998 identified in the Colorado Responds for Children With Special Needs and linked with birth certificate data. There were 189 infants with RA and 940 control infants without RA on the study. The incidence of RA is approximately 1 per 2,900 births. Seventy-six infants (40.6%) born with RA were girls, and 111 infants (59.4%) were boys (P = 0.02). Preexisting diabetes mellitus in the mother was a significant factor associated with RA (adjusted odds ratio (OR), 4.98; 95% confidence interval (CI), 1.08 to 22.93) while controlling for maternal age, maternal race, and alcohol exposure. Black maternal race also was significantly associated with the development of RA (adjusted OR, 2.19; 95% CI, 1.26 to 3.95) while controlling for other factors. Maternal age younger than 18 years, maternal education less than 12 years, alcohol exposure, and infant sex approached significance. RA is a relatively common congenital malformation of the urinary tract. This condition appears to have a multifactorial cause, with a combination of genetic and environmental factors. Further research is needed to show a better understanding of these risk factors. Copyright 2002 by the National Kidney Foundation, Inc.