Prenatal diagnosis of pelvic kidneys

Abstract

Pelvic kidneys may be detected in the prenatal period using ultrasound. However, detection may be difficult and accurate counselling for the parents is restricted by the paucity of data on such cases. This study compares prenatal and postnatal findings in fetuses with a pelvic kidney. Fetuses with a suspected pelvic kidney were identified by retrospective review of the fetal medicine unit computerised databases. The sonographic features of both kidneys were recorded and compared to postnatal imaging. Nine cases were identified with outcome data available in seven. At the time of diagnosis three pelvic kidneys were of normal size and echogenicity, but two regressed during pregnancy. Of the remaining four, two were multicystic and two dysplastic. In one, the contralateral kidney appeared multicystic and the pregnancy was terminated. In one other case the pelvic kidney appeared normal but the contralateral kidney and ureter were dilated. In all remaining cases, the contralateral kidney appeared normal, with five showing compensatory hypertrophy. Postnatal imaging confirmed the diagnosis in all cases. One contralateral kidney which showed compensation during pregnancy was found to be duplex postnatally.