Maternal Physiologic Renal Pelvis Dilatation in Pregnancy: Sonographic Reference Data.

Objectives: The purpose of this study was to produce sonographic reference data for maternal renal pelvis dilatation in asymptomatic pregnant women.

Methods: A prospective cross-sectional study was undertaken on pregnant women presenting for outpatient obstetric imaging. For each side, the renal length and axial anteroposterior diameter of the renal pelvis were measured.