title: Is earlier administration of human chorionic gonadotropin (hCG) associated with the probability of pregnancy in cycles stimulated with recombinant follicle-stimulating hormone and gonadotropin-releasing hormone (GnRH) antagonists? A prospective randomized trial.
abstract: OBJECTIVE
  To evaluate the association of timing of hCG administration and probability of pregnancy in patients stimulated with recombinant FSH/GnRH antagonists for IVF.
  
  
  METHODS
  Prospective randomized controlled clinical trial.
  
  
  METHODS
  Dutch-speaking Free University of Brussels.
  
  
  METHODS
  One hundred twenty patients, aged <40 years, treated by IVF or intracytoplasmic sperm injection.
  
  
  METHODS
  Ovarian stimulation was achieved using recombinant FSH starting on day 2 of the menstrual cycle at a fixed dose. To inhibit premature LH surge, daily GnRH antagonist was used from day 6 of stimulation. Triggering of final oocyte maturation was performed using 10,000 IU of hCG. Patients were randomized to receive hCG either as soon as three or more follicles of size ≥16 mm were present on ultrasonography (early-hCG group) or 1 day after the above criterion was met (late-hCG group).
  
  
  METHODS
  Ongoing pregnancy rate.
  
  
  RESULTS
  Significant differences were observed between the early-hCG and the late-hCG group regarding E(2) (1,388 ± 931 [mean ± SD] vs. 2,040 ± 1,231 pg/mL, respectively) and P (0.8 ± 0.3 vs. 1.1 ± 0.5 ng/mL, respectively) levels on the day of hCG administration and the number of metaphase II oocytes (9.2 ± 7.1 vs. 6.1 ± 4.9, respectively). No significant differences were observed between the early-hCG and the late-hCG group regarding positive hCG (46.2% vs. 50%, respectively) and ongoing pregnancy rates (34.6% vs. 40.7%, respectively).
  
  
  CONCLUSIONS
  The current study provides evidence that earlier administration of hCG is not associated with the probability of pregnancy in cycles stimulated with recombinant FSH and GnRH antagonists.
authors.affiliation: Centre for Reproductive Medicine, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium. mimikyrou@yahoo.gr
authors.forename: Dimitra
authors.initials: D
authors.lastname: Kyrou
authors.forename: Efstratios M
authors.initials: EM
authors.lastname: Kolibianakis
authors.forename: Human M
authors.initials: HM
authors.lastname: Fatemi
authors.forename: Basil C
authors.initials: BC
authors.lastname: Tarlatzis
authors.forename: Herman
authors.initials: H
authors.lastname: Tournaye
authors.forename: Paul
authors.initials: P
authors.lastname: Devroey
mesh_terms: D000328:Adult; D001530:Belgium; D006063:Chorionic Gonadotropin / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage*; D005307:Fertilization in Vitro; D043373:Follicle Stimulating Hormone, Human / Q000008:administration & dosage*; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors*; D006727:Hormone Antagonists / Q000008:administration & dosage*; D006801:Humans; D007246:Infertility / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D010062:Ovulation Induction / Q000379:methods*; D010865:Pilot Projects; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000008:administration & dosage; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; D043373:Follicle Stimulating Hormone, Human; D006727:Hormone Antagonists; D011994:Recombinant Proteins; D007987:Gonadotropin-Releasing Hormone