Prenatal diagnosis of fetal urinary pathology with ultrasound.

Forty-six cases of fetal urinary malformations diagnosed by ultrasound are described. A reliable prenatal diagnosis is extremely important since it may offer options for pregnancy termination or may change obstetric management in the third trimester. Ultrasound criteria necessary for the diagnosis are: (i) bilateral multicystic kidneys, (ii) loss of renal architecture, (iii) non-visualization of the fetal bladder, (iv) absence of amniotic fluid, and (v) urinary dilatation. Thirty-six of the 46 cases of fetal urinary pathology had postnatal confirmation of the diagnosis. No false positive diagnosis was observed. All 19 fetuses with obstructive uropathy were observed for more than 3 weeks. Postnatal function was normal in 12 (63%) fetuses with obstructive uropathy. It is concluded that ultrasound is a valuable tool in the detection of fetal urinary pathology.