Correlation of Prenatal Renal Pelvic Anteroposterior Diameter with Outcome in Infancy

PURPOSE: We attempted to correlate prenatal renal pelvic anteroposterior diameter with outcome in infancy. MATERIAL AND METHODS: Between May 1992 and March 1994 we identified 27 cases of fetal hydronephrosis in which renal pelvic anteroposterior diameter was 4 mm. or greater before 33 weeks of gestation and 7 mm. or greater at or after 33 weeks of gestation. RESULTS: Hydronephrosis was bilateral in 18 fetuses and unilateral in 9. Shortly after birth radiological assessment revealed vesicoureteral reflux in 6 neonates, ureteropelvic junction obstruction in 6, extrarenal pelves in 3 and persistent nonobstructive hydronephrosis in 4. Radiological evaluation was normal in 8 newborns. CONCLUSIONS: When these screening criteria for hydronephrosis are met prenatally a complete radiological assessment should be done following birth.