The prevalence and pattern of congenital anomalies of the urinary tract detected by intravenous urography in Kuwait.

ABSTRACT

We conducted a prospective population-based study in Kuwait to determine the prevalence and pattern of previously undiagnosed congenital anomalies of urinary tract in patients undergoing intravenous urography (IVU) and to examine the demographic factors associated with these anomalies. The study included 2398 consecutive patients undergoing IVU, for various indications, in all the six public hospitals in Kuwait, during the period 1 June 1999-30 September 2000. Patients were also interviewed to obtain selected demographic information. Multiple logistic regression was used to identify factors associated with the anomalies. The average age (+/- SD) of the patients (1623 males, 775 females) was 39.2 +/- 15.1 years. A total of 335 anomalies (12.1% in males, 17.9% in females; p < 0.001) were detected in 300 (12.5%) patients (10.9% males, 15.9% females; p < 0.01). About half (47.2%) of the anomalies involved the kidney, 28.4% renal pelvis, 22.4% ureters, and 2.1% bladder. Multiple regression analysis showed that age < 20 years (odds ratio (OR) = 12.5; 95% confidence interval (95% CI) 7.0-22.3) female gender (OR = 1.5; 95% CI 1.2-2.0) Kuwaiti nationality (OR = 1.7; 95% CI 1.2-2.3) and family history of congenital malformation (OR = 3.8; 95% CI 2.2-6.6) were independently associated with the anomalies of the urinary tract. Overall, 42% of the patients reported a consanguineous marriage between their parents. The frequency of anomalies was higher in individuals who had consanguineous parents (13.8 vs. 11.6%; OR = 1.2) but this positive association did not reach statistical significance. Considering the relatively high prevalence of previously undiagnosed congenital anomalies of the urinary tract, it is important to establish clinical guidelines for early detection and management of these conditions to decrease the associated morbidity and mortality.