ANTENATAL DIAGNOSIS OF FETAL PELVIC KIDNEYS

Objective: To review our experience with the antenatal detection and subsequent neonatal outcome of fetuses with a pelvic kidney. Methods: A retrospective review of 25,551 obstetric ultrasound examinations performed after 16 weeks' gestation identified 13 cases of fetal pelvic kidneys (one per 1965 examinations). Results: Three pelvic kidneys were dysplastic; the remainder appeared sonographically normal. Seven pelvic kidneys were measured; five were smaller than expected for gestational age. Associated anomalies were detected in three cases. Conclusions: Careful second- and third-trimester ultrasound examinations can detect an absence of the kidney in the renal fossa. Evaluating the migratory path of the kidney from the pelvis to the renal fossa will frequently result in detection of an ectopic kidney.