title: Prolongation of the follicular phase in in vitro fertilization results in a lower ongoing pregnancy rate in cycles stimulated with recombinant follicle-stimulating hormone and gonadotropin-releasing hormone antagonists.
abstract: OBJECTIVE
  To assess the effect of altering the timing of hCG administration on ongoing pregnancy rates in patients stimulated with recombinant FSH (rec-FSH) and GnRH antagonists for IVF.
  
  
  METHODS
  Prospective, randomized, controlled trial.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Four hundred thirteen patients undergoing IVF.
  
  
  METHODS
  Rec-FSH stimulation starting on day 2 of the cycle combined with daily GnRH antagonist starting on day 6 of stimulation. Patients were randomized to receive 10000 IU of hCG either as soon as at least three follicles were >or=17 mm on ultrasound (early-hCG group, 208 patients) or 2 days later after this criterion was met (late-hCG group, 205 patients).
  
  
  METHODS
  Ongoing pregnancy rate.
  
  
  RESULTS
  Fertilization rates and number and quality of embryos transferred did not differ between the two groups. However, a significantly lower ongoing pregnancy rate was present in the late-hCG as compared with the early-hCG group (25.0% vs. 35.6%, respectively).
  
  
  CONCLUSIONS
  Prolongation of the follicular phase in patients stimulated with rec-FSH and GnRH antagonists for IVF does not affect oocyte or embryo quality but is associated with a significantly lower ongoing pregnancy rate.
authors.affiliation: Centre for Reproductive Medicine, Dutch-Speaking Brussels Free University, Brussels, Belgium. stratis@easynet.be
authors.forename: Efstratios M
authors.initials: EM
authors.lastname: Kolibianakis
authors.forename: Carola
authors.initials: C
authors.lastname: Albano
authors.forename: Michel
authors.initials: M
authors.lastname: Camus
authors.forename: Herman
authors.initials: H
authors.lastname: Tournaye
authors.forename: André C
authors.initials: AC
authors.lastname: Van Steirteghem
authors.forename: Paul
authors.initials: P
authors.lastname: Devroey
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000627:therapeutic use*; D005498:Follicular Phase; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors*; D006728:Hormones / Q000627:therapeutic use*; D006801:Humans; D006080:Ovarian Follicle / Q000000981:diagnostic imaging; D010062:Ovulation Induction; D011247:Pregnancy; D018873:Pregnancy Rate; D011994:Recombinant Proteins / Q000627:therapeutic use; D013997:Time Factors; D014463:Ultrasonography
chemical_list: D006063:Chorionic Gonadotropin; D006728:Hormones; D011994:Recombinant Proteins; D007987:Gonadotropin-Releasing Hormone; D005640:Follicle Stimulating Hormone