title: Clinical outcomes from mature oocytes derived from preovulatory and antral follicles: reflections on follicle physiology and oocyte competence.
abstract: OBJECTIVE
  The aim of this retrospective study was to compare the competence of oocytes obtained from preovulatory and antral follicles.
  
  
  METHODS
  Mature oocytes from preovulatory follicles were retrieved from women selected for standard IVF treatment (Group A). Mature oocytes from antral follicles were recovered from women undergoing hCG-primed in vitro maturation (IVM) treatment (Group B). Patients groups were matched for age, BMI, FSH, AMH and antral follicle count (AFC) values. In vivo matured oocytes from both groups were microinjected and resulting embryos were culture and selected on day 3 for embryo transfer.
  
  
  RESULTS
  Oocyte pick-ups (OPU) were 315 and 204 in Groups A and B, respectively. Fertilization rates were comparable (72.8 and 75.9 %, respectively; P = 0.137). In Group A, in which the average number of embryos transferred was higher, clinical pregnancy rates per OPU (37.5 %) and embryo transfer (38.4 %) were superior in comparison to Group B (27.0 %, P = 0.013; 29.4 %, P = 0.041; respectively). On the other hand, implantation rates (Group A, 23.7 %; Group B, 20.8 %) and proportions of babies born per transferred embryo (Group A, 19.5 %; Group B, 16.9 %) were similar (P = 0.528 and 0.332, respectively).
  
  
  CONCLUSIONS
  Overall, this suggests that oocyte competence is already achieved at the antral stage of follicle development.
authors.affiliation: Biogenesi Reproductive Medicine Centre, Istituti Clinici Zucchi, Via Zucchi, 24, Monza, Italy.
authors.forename: Rubens
authors.initials: R
authors.lastname: Fadini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Coticchio
authors.forename: Fausta
authors.initials: F
authors.lastname: Brambillasca
authors.forename: Mario
authors.initials: M
authors.lastname: Mignini Renzini
authors.forename: Paola V
authors.initials: PV
authors.lastname: Novara
authors.forename: Claudio
authors.initials: C
authors.lastname: Brigante
authors.forename: Elena
authors.initials: E
authors.lastname: De Ponti
authors.forename: Mariabeatrice
authors.initials: M
authors.lastname: Dal Canto
mesh_terms: D000328:Adult; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000379:methods; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques; D016015:Logistic Models; D008297:Male; D009865:Oocytes / Q000502:physiology*; D006080:Ovarian Follicle / Q000502:physiology*; D010060:Ovulation / Q000502:physiology*; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D016896:Treatment Outcome