title: Comparison of two sperm processing techniques for low complexity assisted fertilization: sperm washing followed by swim-up and discontinuous density gradient centrifugation.
abstract: OBJECTIVE
  This study aimed to assess and compare sperm motility, concentration, and morphology recovery rates, before and after processing through sperm washing followed by swim-up or discontinuous density gradient centrifugation in normospermic individuals.
  
  
  METHODS
  Fifty-eight semen samples were used in double intrauterine insemination procedures; 17 samples (group 1) were prepared with sperm washing followed by swim-up, and 41 (group 2) by discontinuous density gradient centrifugation. This prospective non-randomized study assessed seminal parameters before and after semen processing. A dependent t-test was used for the same technique to analyze seminal parameters before and after semen processing; an independent t-test was used to compare the results before and after processing for both techniques.
  
  
  RESULTS
  The two techniques produced decreases in sample concentration (sperm washing followed by swim-up: P<0.000006; discontinuous density gradient centrifugation: P=0.008457) and increases in motility and normal morphology sperm rates after processing. The difference in sperm motility between the two techniques was not statistically significant. Sperm washing followed by swim-up had better morphology recovery rates than discontinuous density gradient centrifugation (P=0.0095); and the density gradient group had better concentration recovery rates than the swim-up group (P=0.0027).
  
  
  CONCLUSIONS
  The two methods successfully recovered the minimum sperm values needed to perform intrauterine insemination. Sperm washing followed by swim-up is indicated for semen with high sperm concentration and better morphology recovery rates. Discontinuous density gradient centrifugation produced improved concentration recovery rates.
authors.affiliation: Center of Human Reproduction of São Jose do Rio Preto - São José do Rio Preto - SP, Brazil.
authors.forename: Cássio L
authors.initials: CL
authors.lastname: Fácio
authors.affiliation: Center of Human Reproduction of São Jose do Rio Preto - São José do Rio Preto - SP, Brazil.
authors.forename: Lígia F
authors.initials: LF
authors.lastname: Previato
authors.affiliation: Center of Human Reproduction of São Jose do Rio Preto - São José do Rio Preto - SP, Brazil.
authors.forename: Ligiane A
authors.initials: LA
authors.lastname: Machado-Paula
authors.affiliation: Center of Human Reproduction of São Jose do Rio Preto - São José do Rio Preto - SP, Brazil.
authors.forename: Paulo Cs
authors.initials: PC
authors.lastname: Matheus
authors.affiliation: Center of Human Reproduction of São Jose do Rio Preto - São José do Rio Preto - SP, Brazil.
authors.forename: Edilberto
authors.initials: E
authors.lastname: Araújo
keywords: Intrauterine insemination; discontinuous concentration gradient; semen processing; swim-up