Ultrasound screening for congenital pyelectasis in term pregnancies.

The purpose of this study was to compare the role of antenatal ultrasound screening for congenital pyelectasis at term with postnatal screening. An ultrasonographic prospective study of 231 fetuses of low-risk pregnancies was performed, evaluating the renal pelvis at term (38 to 42 weeks gestation) and after birth (first and third months of life). Cut-off points used were 9 mm antenatally, and 10 and 12 mm, respectively postnatally, all in an anteroposterior view.