title: Reproducibility and reliability of repeated semen analyses in male partners of subfertile couples.
abstract: OBJECTIVE
  To determine the precise degree of variability that is represented by the reproducibility and reliability of semen analysis. The general assumption is that semen analyses need to be repeated because of a high degree of within-individual variability. However, the precise degree of variability is not well established in male partners of subfertile couples.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Two university hospitals in the Netherlands, which routinely perform two semen analyses in the male partner of subfertile couples.
  
  
  METHODS
  Male partners of subfertile couples.
  
  
  METHODS
  None.
  
  
  METHODS
  We assessed the test-retest reproducibility, by calculating the coefficient of variation (CV(w)) for five semen parameters. The CV(w) expresses, on a relative scale, the degree of closeness of repeated measurements taken in the same subject. We also estimated the reliability of these semen parameters, in terms of the intraclass correlation coefficient, which expresses the ratio of the between-subject variability over the total variability.
  
  
  RESULTS
  We analyzed the data of 5,240 men and found that the CV(w) of all semen parameters ranged from 28% to 34%. The intraclass correlation coefficients of these semen parameters were moderate to high: volume: 0.70; concentration: 0.89; motility: 0.58; morphology: 0.60; total motile count: 0.73.
  
  
  CONCLUSIONS
  This study affirmed the presumed large within-subject variability and the limited reproducibility of semen analyses in subfertile men. Whether this degree of variability within men justifies one or more repetitions of the semen analysis in view of consequences for clinical management should be the topic of future studies. Until then it seems reasonable to perform two semen analyses.
authors.affiliation: Center for Reproductive Medicine, Academic Medical Center, Department of Obstetrics and Gynecology, Amsterdam, the Netherlands. e_leushuis@hotmail.com
authors.forename: Esther
authors.initials: E
authors.lastname: Leushuis
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: van der Steeg
authors.forename: Pieternel
authors.initials: P
authors.lastname: Steures
authors.forename: Sjoerd
authors.initials: S
authors.lastname: Repping
authors.forename: Patrick M M
authors.initials: PM
authors.lastname: Bossuyt
authors.forename: Marinus A
authors.initials: MA
authors.lastname: Blankenstein
authors.forename: Ben Willem J
authors.initials: BW
authors.lastname: Mol
authors.forename: Fulco
authors.initials: F
authors.lastname: van der Veen
authors.forename: Peter G A
authors.initials: PG
authors.lastname: Hompes
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005191:Family Characteristics; D005260:Female; D005298:Fertility / Q000502:physiology; D006801:Humans; D007246:Infertility / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D015203:Reproducibility of Results; D012189:Retrospective Studies; D055101:Semen Analysis / Q000379:methods* / Q000592:standards; D012747:Sexual Partners