has part has part characteristic of has modifier Abnormal renal pelvis morphology Fetal pyelectasis The renal pelvis is the part of the kidney that collects urine. Fetal pyelectasis is a prenatal ultrasound finding that is diagnosed with enlargement of the renal pelvis from 4 to 10 millimeters. In many cases, fetal pyelectasis resolves spontaneously. Note that dilatation of the renal pelvis to more than 10 mm is referred to as severe pyelectasis or hydronephrosis. Measurements less than 5mm are normal, should not be designated as pyelectasis, and should not be reported (PMID:16100637). Fetal ultrasound soft marker Abnormal fetal genitourinary system morphology abnormal increased size renal pelvis