[Fetal bilateral obstructive uropathies: ultrasound findings during pregnancy and postnatal outcomes].

Purpose: to verify the association between ultrasonographic signs during gestation and post-delivery evolution in fetuses with bilateral obstructive uropathies, followed up in an expectant way.

Methods: fetuses with bilateral obstructive uropathies presenting severe oligoamnios and narrow thorax have been compared with fetuses with bilateral obstructive uropathies without those alterations, concerning the presence or absence of cysts in both kidneys, and the presence or absence of parenchymal hyperechogenicity in both kidneys. Cases of neonatal death were compared with cases of neonatal discharge from the nursery, regarding the same renal echographic aspects mentioned above, the presence of severe oligoamnios and narrow thorax. The sensitivity, specificity, positive and negative predictive value of the presence of bilateral renal cysts, bilateral renal hyperechogenicity, severe oligoamnios and narrow fetal thorax for the neonatal death were calculated.

Results: severe oligoamnios and narrow thorax were more frequent (p=0.03; p<0.001) in fetuses with bilateral renal cysts, as compared to those with echographically normal renal parenchyma. Neonatal death was more frequent among cases with severe oligoamnios (p<0.001), narrow thorax (p<0.001) and bilateral renal cysts (p<0.002), when respectively compared with cases without those alterations. The best values of sensitivity, specificity, positive and negative predictive value for the death of neonatal/breastfeeding infants were obtained using the echographic aspect of narrow thorax, and were 81.8, 100, 100 and 79.3%, respectively.

Conclusions: in cases of fetuses with bilateral obstructive uropathies followed up in an expectant way, the ultrasonographic signs more associated to bad prognosis are severe oligoamnios, narrow fetal thorax and presence of bilateral renal cysts.