Antenatal detection of renal abnormalities.

The aim of this retrospective study is to assess the value of routine ultrasonography in the detection of renal abnormalities. Twenty-nine pregnancies (one set of twins) with suspected renal abnormalities (i.e. renal cystic spaces, oligohydramnios or hyperechoic kidneys) were delivered over a two year period (1.8.1987-31-7-1989) in a unit where 90% of pregnancies (6,562) were scanned routinely at 18-20 weeks gestation or later, if booking for confinement was delayed. In pregnancies with suspected anomalies prenatal ultrasound was performed monthly until 28 weeks and fortnightly until delivery. Non survivors [5] had histological or postmortem examination. Liveborn infants [25] had renal ultrasonography in the neonatal period and paediatric follow-up if abnormal. Sixteen (53%) of the 30 cases (one set of twins) suspected of renal abnormalities by routine prenatal ultrasonography had renal anomalies confirmed postnatally. Five women were non survivors, all of which had associated anomalies. In the eleven survivors the diagnoses were pelvi-ureteric junction obstruction [6], renal dysplasia [2], vesicoureteric reflux [2] and suspected ureterocele [1]. Fourteen infants with pelvicalyceal dilatation had normal postnatal renal ultrasound. Although abnormal prenatal renal ultrasound is a useful indicator of postnatal disease and aids decisions on the management of pregnancy, further large collaborative studies with extended paediatric follow-up are required to assess the significance of pelvicalyceal dilatation.