Prenatal diagnosis and postnatal outcome of pelvic kidneys.

OBJECTIVE

To assess the prevalence of pelvic kidneys during prenatal sonographic examinations in the second and third trimesters and to examine postnatal outcome.

METHODS

Prenatal sonographic findings and postnatal follow-up data of fetuses with prenatal diagnosis of pelvic kidneys were analyzed. Routine (n = 10 079) and indicated (n = 17 732) second and third trimester scans were performed in 27 811 fetuses. A pelvic kidney was defined as one located within the fetal bony pelvis and in close approximation to the bladder. Postnatal evaluation consisted of renal ultrasound and/or dimercapto-succinic acid scan.

RESULTS

A total of 36 newborns with postnatally confirmed pelvic kidneys were included in this analysis. Median gestational age at diagnosis was 25 weeks; half (18/36) were recognized after 24 weeks. The prevalence of pelvic kidneys in this cohort was 0.14%. Postnatally impaired renal function was present in 33% of the pelvic kidneys of children, but overall renal function remained normal. No serious complications occurred in the 31 fetuses with long-term follow-up, except in 1 case, which required nephrectomy due to multicystic dysplasia of the pelvic kidney.

CONCLUSION

Pelvic kidneys are common and can be easily detected prenatally. Prognosis is favorable in the vast majority of the cases.