title: Isolated fetal hydronephrosis: beware the effect of bladder filling.
abstract: The aim was to assess the role that fetal bladder size has in the determination of fetal hydronephrosis. Forty-three fetuses were evaluated for fetal hydronephrosis in the second trimester of pregnancy. Anteroposterior measurements of the renal pelvis were obtained with a full bladder and again when the bladder emptied in each fetus. Statistical analysis was performed using the Spearman rank order correlation coefficient to assess the relationship between bladder status and renal dilation. The anteroposterior size of the fetal renal pelvis diminished from 6.8 +/- 1.8 mm on a full bladder scan to 4.5 +/- 1.6 mm when the bladder was emptied (P < 0.001). Fifty-three per cent of the fetuses whose renal pelvic measurements were 5 mm or more on a full bladder scan had normal-appearing renal pelvises when their bladders emptied. The status of the fetal bladder should be considered when evaluating fetal hydronephrosis.
authors.affiliation: Division of Maternal-Fetal Medicine, North Shore University Hospital-Cornell University Medical College, Manhasset, NY 11030, USA.
authors.forename: B M
authors.initials: BM
authors.lastname: Petrikovsky
authors.forename: M I
authors.initials: MI
authors.lastname: Cuomo
authors.forename: E P
authors.initials: EP
authors.lastname: Schneider
authors.forename: L J
authors.initials: LJ
authors.lastname: Wyse
authors.forename: H L
authors.initials: HL
authors.lastname: Cohen
authors.forename: M
authors.initials: M
authors.lastname: Lesser
mesh_terms: D003951:Diagnostic Errors; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging*; D007682:Kidney Pelvis / Q000000981:diagnostic imaging; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011379:Prognosis; D016216:Ultrasonography, Prenatal; D001743:Urinary Bladder / Q000000981:diagnostic imaging* / Q000502:physiology