title: Influence of the number of motile spermatozoa inseminated and of their morphology on the success of intrauterine insemination.
abstract: BACKGROUND
  Although intrauterine insemination (IUI) is one of the most common assisted reproductive technology methods in the world, the relative influence of various semen characteristics on the likelihood of a successful outcome is controversial. The aim of our study was to assess the results of IUI as a function of both the number of motile spermatozoa inseminated (NMSI) and the percentage of morphologically normal spermatozoa after preparation.
  
  
  METHODS
  This was a retrospective study of 889 couples who underwent 2564 IUI cycles of ovarian stimulation with HMG or recombinant FSH in our centre between January 1991 and December 2000.
  
  
  RESULTS
  A total of 331 clinical pregnancies were obtained, for a pregnancy rate/cycle of 12.91%. When the NMSI was < 1 x 10(6), the pregnancy rate/cycle was significantly lower (3.13%) than in any of the subgroups with NMSI > or = 2 x 10(6). Sperm morphology, assessed before or after preparation, was not in itself a significant factor that affected the likelihood of IUI success. Nonetheless, when the post-migration rate of normal sperm was < 30%, the pregnancy rate/cycle was 5.43% when NMSI was < 5 x 10(6) and 18.42% when NMSI was > or = 5 x 10(6) (P = 0.008). Pregnancy rates did not differ significantly according to NMSI when the percentage of normal sperm after preparation was > or = 30%, or according to percentage of normal sperm when the NMSI was > or = 5 x 10(6).
  
  
  CONCLUSIONS
  Our results show that a minimum of 5 x 10(6) motile spermatozoa should be inseminated when the normal morphology of the sperm after preparation is < 30%; the quantity compensates at least in part for the defective quality. If this threshold of NMSI cannot be obtained, IVF should be recommended.
authors.affiliation: Obstetric & Gynecology Department, Poissy-Saint Germain Hospital, 78300 Poissy, Versailles, Saint Quentin en Yveline University, France. bob.wainer@wanadoo.fr
authors.forename: Robert
authors.initials: R
authors.lastname: Wainer
authors.forename: Martine
authors.initials: M
authors.lastname: Albert
authors.forename: Agnès
authors.initials: A
authors.lastname: Dorion
authors.forename: Marc
authors.initials: M
authors.lastname: Bailly
authors.forename: Marianne
authors.initials: M
authors.lastname: Bergère
authors.forename: Raoul
authors.initials: R
authors.lastname: Lombroso
authors.forename: Myriam
authors.initials: M
authors.lastname: Gombault
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Selva
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007317:Insemination, Artificial, Homologous; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000648:ultrastructure*