title: Age at cryptorchidism diagnosis and orchiopexy in Denmark: a population based study of 508,964 boys born from 1995 to 2009.
abstract: OBJECTIVE
  Early treatment for cryptorchidism may be necessary to preserve fertility. International guidelines now recommend that congenital cryptorchidism be treated with orchiopexy before age 1 year. Acquired cryptorchidism should be treated at presentation. To our knowledge the rate of adherence to these guidelines in recent years is unknown. Thus, we present data on age at cryptorchidism diagnosis and orchiopexy in recent Danish birth cohorts.
  
  
  METHODS
  A population of 508,964 Danish boys born alive from January 1, 1995 to December 31, 2009 was identified using the Danish Civil Registration System. Five birth cohorts were defined, including 1995 to 1997, 1998 to 2000, 2001 to 2003, 2004 to 2006 and 2007 to 2009. The boys were followed in the Danish National Patient Registry for a diagnosis of cryptorchidism and for an orchiopexy procedure. Data were analyzed using the Kaplan-Meier estimator and Cox regression models.
  
  
  RESULTS
  During followup 10,094 boys were diagnosed with cryptorchidism, of whom 5,473 underwent orchiopexy. Mean age at diagnosis in boys followed at least 6 years was 3.3 years (95% CI 3.3-3.4) in the 1995 to 1997 cohort, 3.1 (95% CI 3.1-3.2) in the 1998 to 2000 cohort and 2.9 (95% CI 2.8-2.9) in the 2001 to 2003 cohort while mean age at orchiopexy was 3.8 (3.7-3.9), 3.6 (3.5-3.7) and 3.3 years (3.2-3.4), respectively.
  
  
  CONCLUSIONS
  In the more recent birth cohorts of 1995 to 2009 we observed a shift toward younger age at cryptorchidism diagnosis and orchiopexy.
authors.affiliation: Perinatal Research Unit, Department of Pediatrics, Aarhus University Hospital Skejby, Aarhus, Denmark. morten@sondergaard-jensen.dk
authors.forename: Morten Søndergaard
authors.initials: MS
authors.lastname: Jensen
authors.forename: Lars Henning
authors.initials: LH
authors.lastname: Olsen
authors.forename: Ane Marie
authors.initials: AM
authors.lastname: Thulstrup
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Bonde
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
authors.forename: Tine Brink
authors.initials: TB
authors.lastname: Henriksen
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000367:Age Factors; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003456:Cryptorchidism / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D003718:Denmark / Q000453:epidemiology; D042241:Early Diagnosis; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D056126:Orchiopexy / Q000379:methods*; D011159:Population Surveillance; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors