title: Timing ovulation for intrauterine insemination with a GnRH antagonist.
abstract: BACKGROUND
  We aimed to assess the efficacy of a GnRH antagonist in intrauterine insemination (IUI) cycles to increase number of mature ovulatory follicles and pregnancy rates.
  
  
  METHODS
  Prospective randomized study. Women (18-38 years old) with primary/secondary infertility were included. Eighty-two patients were randomly assigned to controlled ovarian stimulation (COS) consisting of rFSH + GnRH antagonist or rFSH alone.
  
  
  RESULTS
  A non-significant increase in the total amount of rFSH was seen in the GnRH antagonist group (707+/-240 IU) with respect to the control group (657+/-194 IU). The number of mature follicles (> or =16 mm) was significantly higher in the GnRH antagonist group than in the control group (2.4+/-1.4 versus 1.7+/-1.2, P<0.05). Pregnancy rates were significantly increased in the group of patients receiving the GnRH antagonist (38%) compared to the control group (14%). The only non-single pregnancy (triplets) occurred in the antagonist group.
  
  
  CONCLUSIONS
  In this preliminary study, adding the GnRH antagonist to the COS protocol for IUI cycles significantly increased pregnancy rates. Nevertheless, these results may not be associated directly with the antagonist itself but with the fact that more mature ovulatory follicles are present by the day of the hCG. Finally, the risk for multiple gestations needs to be carefully evaluated.
authors.affiliation: Clínica de Medicina de la Reproducción y Ginecología FIVMadrid, Madrid and Unidad de Reproducción, Hospital Severo Ochoa, Madrid, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Gómez-Palomares
authors.forename: B
authors.initials: B
authors.lastname: Juliá
authors.forename: B
authors.initials: B
authors.lastname: Acevedo-Martín
authors.forename: M
authors.initials: M
authors.lastname: Martínez-Burgos
authors.forename: E R
authors.initials: ER
authors.lastname: Hernández
authors.forename: E
authors.initials: E
authors.lastname: Ricciarelli
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors; D006727:Hormone Antagonists / Q000008:administration & dosage*; D006801:Humans; D007315:Insemination, Artificial / Q000379:methods*; D006080:Ovarian Follicle / Q000187:drug effects; D010060:Ovulation / Q000187:drug effects*; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies
chemical_list: D006727:Hormone Antagonists; D007987:Gonadotropin-Releasing Hormone; D005640:Follicle Stimulating Hormone; C061018:ganirelix