title: Postnatal longitudinal evaluation of children diagnosed with prenatal hydronephrosis: insights in natural history and referral pattern.
abstract: OBJECTIVE
  Clinical significance and management of prenatal hydronephrosis (PNH) are sources of debate. Existing studies are flawed with biased cohorts or inconsistent follow-up. We aimed to evaluate the incidence of pathology in a large cohort of PNH and assess the biases and outcomes of this population.
  
  
  METHODS
  We reviewed 1034 charts of fetuses with PNH. Records of delivered offspring were reviewed at a pediatric center and analyzed with respect to prenatal and postnatal pathology and management.
  
  
  RESULTS
  Prenatal resolution of hydronephrosis occurred in 24.7% of pregnancies. On first postnatal ultrasound, some degree of dilatation was present in 80%, 88% and 95% of mild, moderate and severe PNH cases, respectively. At the end of follow-up, hydronephrosis persisted in 10%, 25% and 72% of children, respectively. Incidence of vesicoureteral reflux did not correlate with severity of PNH. Children with postnatal workup had more severe PNH than those without.
  
  
  CONCLUSIONS
  Despite prenatal resolution totalizing 25%, pelvic dilatation persisted on first postnatal imaging in most cases, thus justifying postnatal ultrasound evaluation. Whereas most mild cases resolved spontaneously, a quarter of moderate and more than half of severe cases required surgery. Patients with postnatal imaging and referral had more severe PNH, which could result in overestimation of pathology.
authors.affiliation: Department of Urology, Children's Hospital, Boston, MA, USA.
authors.forename: Joao A B A
authors.initials: JA
authors.lastname: Barbosa
authors.forename: Jeanne S
authors.initials: JS
authors.lastname: Chow
authors.forename: Carol B
authors.initials: CB
authors.lastname: Benson
authors.forename: Marco A
authors.initials: MA
authors.lastname: Yorioka
authors.forename: Alexandre S
authors.initials: AS
authors.lastname: Bull
authors.forename: Alan B
authors.initials: AB
authors.lastname: Retik
authors.forename: Hiep T
authors.initials: HT
authors.lastname: Nguyen
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D005315:Fetal Diseases / Q000453:epidemiology; D006801:Humans; D006869:Hydronephrosis / Q000151:congenital / Q000453:epidemiology*; D015994:Incidence; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014517:Ureteral Obstruction / Q000453:epidemiology