title: Fetal obstructive uropathy: is urine sampling useful for prenatal counselling?
abstract: OBJECTIVE
  To evaluate whether fetal urinary sodium and chloride provide clinically useful information in addition to ultrasound in bilateral obstructive uropathy.
  
  
  METHODS
  Sonographic features and urinary concentrations of sodium and chloride were evaluated in fetuses with bilateral obstructive uropathy. After a minimum of 12 months of postnatal follow-up, cases that developed increased serum creatinine (greater than 50 micromol/L) were compared with those that did not.
  
  
  RESULTS
  Of the cases studied, 16/35 died perinatally, all showing anamnios and markedly elevated urinary electrolytes. Of the survivors, ten maintained normal postnatal serum creatinine, whereas nine did not. The frequency of reduced amniotic fluid/olygohydramnios was higher in cases that developed increased serum creatinine (four out of nine) than in those that did not (nil). Sodium above the 95th percentile was 100% specific and 44% sensitive to predict an increased serum creatinine during early infancy, while chloride above the 95th percentile was 70% specific and 56% sensitive. All seven cases in which urinary sodium was elevated and/or amniotic fluid volume was reduced developed renal failure.
  
  
  CONCLUSIONS
  Urine sampling slightly improved renal function prediction, but this must be balanced against its fetal risks.
authors.affiliation: Department of Obstetrics and Gynecology, University of Sao Paulo Medical School Hospital, Sao Paulo, Brazil.
authors.forename: Javier
authors.initials: J
authors.lastname: Miguelez
authors.forename: Victor
authors.initials: V
authors.lastname: Bunduki
authors.forename: Carlos Tadashi
authors.initials: CT
authors.lastname: Yoshizaki
authors.forename: Lilian dos Santos Rodrigues
authors.initials: Ldos S
authors.lastname: Sadek
authors.forename: Vera
authors.initials: V
authors.lastname: Koch
authors.forename: Cleisson Fabio Andrioli
authors.initials: CF
authors.lastname: Peralta
authors.forename: Marcelo
authors.initials: M
authors.lastname: Zugaib
mesh_terms: D001938:Brazil; D003404:Creatinine / Q000097:blood; D004108:Dilatation, Pathologic / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000196:embryology / Q000401:mortality / Q000652:urine; D005260:Female; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012680:Sensitivity and Specificity; D012965:Sodium Chloride / Q000652:urine; D016216:Ultrasonography, Prenatal; D016482:Urinalysis / Q000592:standards*; D014570:Urologic Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000196:embryology / Q000401:mortality / Q000652:urine
chemical_list: D012965:Sodium Chloride; D003404:Creatinine