Posterior urethral valves and vesicoureteral reflux: can prenatal ultrasonography distinguish between these two conditions in male fetuses?

Objective To evaluate prenatal sonographic signs that distinguish male fetuses with posterior urethral valves(PUV) from those with vesicoureteral reflux(VUR). Methods Antenatal data were retrospectively retrieved from all consecutive women delivering between 2003 and 2012 of a male newborn with a postnatal diagnosis of PUV or VUR. Prenatal parameters included fetal bladder characteristics, identification of a dilated posterior urethra, and change in shape and size in the fetal renal pelvisor ureter. Results 136 women gave birth to a male newborn with a postnatal diagnosis of PUV (n = 49) or VUR (n = 87). The presence of posterior urethral dilatation(21 [42.9%] fetuses versus 0 [0%], p = 0.000), a thickened fetal bladder wall (37 [75.5%] versus 4 [4.6%], p = 0.000) and anhydramnios (14 [28.6%] versus 0, p = 0.000) were strongly associated with the postnatal diagnosis of PUV. Change in shape and size in the fetal renal pelvisor ureterwas observed in 15 (17.2%) of 87 children with VUR versus 1 (2.0%) out of 49 with PUV (p = 0.010). Conclusions Prenatal ultrasound may differentiate with reasonable accuracy male fetuses with a postnatal diagnosis of PUV from those with VUR.