Fetal Pyelectasis as Predictor of Decreased Differential Renal Function

Approximately 16% of all fetuses with pyelectasis have 35% or less differential function as newborns, including 36% identified by pyelectasis greater than 10 mm at estimated gestational age 20 to 24 weeks. Fetal pyelectasis greater than 10 mm at estimated gestational age 20 to 24 weeks and greater than 16 mm at greater than 33 weeks is associated with 35% or less differential function in the newborn.