[Urinary tract ultrasonography in newborns with late oligohydramnios]

The aim of this study was to evaluate the value of neonatal renal ultrasonography in the diagnosis of urinary tract malformation pathologies in newborns from pregnancies complicated by late oligohydramnios.

During the period January 1994-October 1997, 119 newborns from pregnancies complicated by oligohydramnios occurring in the third trimester of pregnancy underwent ultrasonography of the urinary tract at our Centre. All newborns had previously undergone prenatal ultrasonography.

Ultrasonography revealed calicopyelic dilatation < 10 mm in 7 newborns (5.8%), 5 of whom had already been reported at the prenatal ultrasonography. One new-born (0.8%) also showed the presence of an ectopic kidney that had not been diagnosed at the prenatal scan. By the next follow-up all the calico-pyelic dilatations had become normal.

Neonatal ultrasonography did not show any alterations to the urinary tract that might be responsible for the reduction of amniotic liquid. We therefore feel that is useful to perform neonatal ultrasonography in those situations in which the onset of oligohydramnios occurred in the second trimester of pregnancy and in cases in which no scan was performed during the prenatal period.