Abstract
Two cases of significant hydronephrosis of pregnancy and their management are detailed. Measurements of calyceal diameters in control and pregnant patients of varying gestational ages are presented. Calyceal dilatation in pre-and postvoid states for all patients examined is compared, with no differences noted. Although there was a general trend toward increasing calyceal diameters throughout pregnancy, high intragroup variation was present in each group. There were no significant differences detected between gestational age groups and between right and left kidneys. Ultrasonography can be used as the initial method of evaluation in symptomatic pregnant patients. The absence of hydronephrosis virtually eliminates obstructive disease, while significant hydronephrosis may be present without disease. The hydronephrosis of pregnancy is highly variable and exhibits wide ranges of physiologic change. Medical management should be based on symptomatology rather than "hydronephrosis" as a pathologic diagnosis.