title: [Contribution of ultrasound signs for the prenatal diagnosis of posterior urethral valves: Experience of 3years at the maternity of the Bicêtre Hospital].
abstract: OBJECTIVE
  Posterior urethral valves (PUV) are the most common cause of renal impairment in boys during early childhood. The aim of this study was to evaluate the value of ultrasound (US) criteria currently used to diagnose PUV.
  
  
  METHODS
  From 2009 to 2012, 31 patients were referred to the Bicêtre Hospital after detection of fetal bilateral hydronephrosis in male fetus. The ultrasound criteria were bladder dilation, thick-walled bladder, urethral dilation ("keyhole sign"), and amniotic fluid volume. Patients were divided in two groups: suspected or not to have PUV.
  
  
  RESULTS
  US diagnosis of PUV was done in 18 fetuses and confirmed in 14 new borns, one of them without prenatal diagnosis. Sensitivity and specificity of US scan were 92.8 and 66.7%. The likelihood ratio (LHR) was 4.8 for a thick-walled bladder, 4.2 for oligohydramnios, 3.6 for the "keyhole sign", 2.4 for bladder dilation and 1.6 for ureteral dilation. The first four signs were combined in four fetuses, all of them with PUV.
  
  
  CONCLUSIONS
  US scan is a very sensitive exam for the diagnosis of PUV but with a low specificity. A thick-walled bladder seems to have a better diagnostic performance than the "keyhole sign".
authors.affiliation: Hôpital Bicêtre, 78, rue du Général-Leclerc, 94275 Le Kremlin-Bicêtre, France. Electronic address: sophie.roy1@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Roy
authors.affiliation: Hôpital Bicêtre, 78, rue du Général-Leclerc, 94275 Le Kremlin-Bicêtre, France.
authors.forename: C
authors.initials: C
authors.lastname: Colmant
authors.affiliation: Hôpital Béclère, 157, rue de la Porte-de-Trivaux, 92140 Clamart, France.
authors.forename: A-G
authors.initials: AG
authors.lastname: Cordier
authors.affiliation: Hôpital Bicêtre, 78, rue du Général-Leclerc, 94275 Le Kremlin-Bicêtre, France.
authors.forename: M-V
authors.initials: MV
authors.lastname: Sénat
mesh_terms: D004108:Dilatation, Pathologic; D005260:Female; D005602:France; D005865:Gestational Age; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging / Q000196:embryology*; D007231:Infant, Newborn; D008297:Male; D016104:Oligohydramnios / Q000000981:diagnostic imaging; D011247:Pregnancy; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal; D014521:Urethra / Q000000981:diagnostic imaging / Q000196:embryology*; D001743:Urinary Bladder / Q000000981:diagnostic imaging / Q000196:embryology
keywords: Diagnostic anténatal; Keyhole sign; Posterior urethral valves; Prenatal ultrasound; Récessus sous-vésical; Valve urètre postérieur