Fetal obstructive uropathies

Abstract

Background: Congenital abnormalities of the urinary system are among the most commonly diagnosed ones during prenatal sonographic examinations. Obstructive uropathies represent the major part of fetal urologic abnormalities. Methods: The retrospective study included a group of neonates in whom isolated obstructive uropathies were found and consequently studied in Tertiary Ultrasound Center at the Department of Perinatology in Ljubljana since January 2002 to December 2006. The types and frequencies of isolated obstructive uropathies were described, the findings before and after birth were compared and the positive predictive value of sonographic measurement was calculated. Results: 52 neonates, all singletons, were included. The group consisted of 32 (61.5 %) boys and 20 (38 %) girls. There were 21 pyelectasies and 8 hydronephroses. The findings matched completely in 22 (42.3 %) cases and partially in 28 (53.8 %) cases. In 2 (3.8 %) cases the findings did not match. We found spontaneous improvement after birth in 18 (62.1 %) cases. The calculated positive predictive value of sonographic examination during pregnancy in our Department equaled 82.7 %. Conclusions: Sonographic examination of the fetal urinary tract has a good positive predictive value (82.7 %). Obstructive uropathies appear more often in boys (61.5 %). The clinical course is better in boys as spontaneous improvement of isolated renal pelvis dilatation occurs in 77.8 % of boys and 36.4 % of girls. Mostly only one or two sonographic follow-up examinations in the third trimester of pregnancy are sufficient. Karyotyping is not necessary with isolated obstructive uropathies.