title: Outcome of isolated fetal renal pyelectasis diagnosed during midtrimester screening ultrasound and cut-off value to predict a persistent or progressive pyelectasis in utero.
abstract: OBJECTIVE
  To define a better cut-off value of the renal pelvis anteroposterior diameter (RPAPD) to predict persistent or progressive pyelectasis during pregnancy.
  
  
  METHODS
  We retrospectively reviewed 8873 women whose fetal RPAPD was measured. Midtrimester pyelectasis was defined as a RPAPD of ≥4 mm. Persistent/progressive pyelectasis was defined as a RPAPD of ≥10 mm before delivery. A RPAPD cut-off value to predict a persistent/progressive pyelectasis was determined by receiver operating characteristic curve analysis.
  
  
  RESULTS
  Among 249 isolated cases of pyelectasis, persistent/progressive pyelectasis was found in 6.9% before delivery. The midtrimester RPAPD cut-off value that best predicted persistent/progressive pyelectasis before delivery was ≥6 mm with sensitivity, specificity, positive and negative predictive values of 64.3%, 88.7%, 30.0%, and 97.1%, respectively.
  
  
  CONCLUSIONS
  Although most cases of midtrimester fetal pyelectasis regress to normal during pregnancy, those with a RPAPD of ≥6 mm in the midtrimester are at higher risk for persistent or progressive pyelectasis.
authors: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Moon-Kyung
authors: MK
authors: Kim
authors: Min-Ji
authors: MJ
authors: Kim
authors: Jung-Joo
authors: JJ
authors: An
authors: Hyun-Hwa
authors: HH
authors: Cha
authors: Suk-Joo
authors: SJ
authors: Choi
authors: Soo-Young
authors: SY
authors: Oh
authors: Cheong-Rae
authors: CR
authors: Roh
authors: Jong-Hwa
authors: JH
authors: Kim
mesh_terms: D000328:Adult; D018450:Disease Progression; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007682:Kidney Pelvis / Q000000981:diagnostic imaging; D008297:Male; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011379:Prognosis; D058536:Pyelectasis / Q000000981:diagnostic imaging*; D012075:Remission, Spontaneous; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal / Q000706:statistics & numerical data