title: Antral follicle responsiveness to follicle-stimulating hormone administration assessed by the Follicular Output RaTe (FORT) may predict in vitro fertilization-embryo transfer outcome.
abstract: BACKGROUND
  Looking for a qualitative marker of ovarian function, we aimed to verify whether responsiveness of antral follicles to FSH administration, as reflected by the Follicular Output RaTe (FORT), is related to their reproductive competence.
  
  
  METHODS
  We studied 322 IVF-ET candidates aged 25-43 years who underwent controlled ovarian hyperstimulation with similar initial FSH doses. Antral follicle (3-8 mm) count (AFC) and pre-ovulatory follicle (16-22 mm) count (PFC) were performed, respectively, at the achievement of pituitary suppression (before FSH treatment) and on the day of hCG administration. The FORT was calculated by PFC × 100/AFC. FORT groups were set according to tercile values: low (<42%; n= 102), average (42-58%; n= 123) and high (>58%; n= 97).
  
  
  RESULTS
  The average FORT was 50.6% (range, 16.7-100.0%). Clinical pregnancy rates per oocyte retrieval increased progressively from the low to the high FORT groups (33.3, 51.2 and 55.7%, respectively, P< 0.003) and such a relationship assessed by logistic regression was independent of the confounding covariates, women's ages, AFC and PFC.
  
  
  CONCLUSIONS
  The observed relationship between IVF-ET outcome and the percentage of antral follicles that effectively respond to FSH administration reaching pre-ovulatory maturation suggests that FORT may be a qualitative reflector of ovarian follicular competence. Further studies with broader inclusion criteria and more personalized protocols are needed to validate these results.
authors.affiliation: AP-HP, Centre de Médecine et Biologie de la Reproduction,  Hôpital Antoine Béclère, Clamart F-92141,  France.
authors.forename: V
authors.initials: V
authors.lastname: Gallot
authors.forename: A L
authors.initials: AL
authors.lastname: Berwanger da Silva
authors.forename: V
authors.initials: V
authors.lastname: Genro
authors.forename: M
authors.initials: M
authors.lastname: Grynberg
authors.forename: N
authors.initials: N
authors.lastname: Frydman
authors.forename: R
authors.initials: R
authors.lastname: Fanchin
mesh_terms: D000328:Adult; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000494:pharmacology*; D006801:Humans; D016015:Logistic Models; D006080:Ovarian Follicle / Q000187:drug effects*; D010062:Ovulation Induction; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D005640:Follicle Stimulating Hormone