title: Serum IGF-1 concentrations following pituitary desensitization do not predict the ovarian response to gonadotrophin stimulation prior to IVF.
abstract: BACKGROUND
  Insulin-like growth factor-1 (IGF-1) is known to play a role in ovarian follicular development augmenting the action of FSH. Low intrafollicular concentrations have been detected in women who respond poorly to gonadotrophins. This study addresses the relationship between serum IGF-1 levels following pituitary desensitization and ovarian response to gonadotrophin stimulation.
  
  
  METHODS
  This is a case-control study of 78 patients undergoing IVF-embryo transfer treatment. Thirty-nine strictly-defined poor responder patients requiring 50 or more ampoules (75 IU FSH) to reach oocyte retrieval were compared with 39 age-matched normal responders, requiring fewer than 50 ampoules. IGF-1 concentrations were determined by extraction radioimmunoassay on serum samples obtained after pituitary desensitization but prior to gonadotrophin stimulation.
  
  
  RESULTS
  Despite highly significant differences in measures of ovarian response between groups, the mean serum IGF-1 concentration was not statistically significantly different between poor and normal responders [(31.5 nmol/l [95% confidence interval (CI) 28.5-34.5] versus 34.5 nmol/l (95% CI 31.8-37.2)] respectively. No correlation between oocyte number or total gonadotrophin used and serum IGF-1 concentration was observed.
  
  
  CONCLUSIONS
  Whilst IGF-1 influences ovarian follicular development this study suggests that serum IGF-1 does not predict ovarian response and does not differentiate between critically-defined poor and normal responders.
authors.affiliation: Department of Biological Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK. Skeay@bio.warwick.ac.uk
authors.forename: S D
authors.initials: SD
authors.lastname: Keay
authors.forename: N H
authors.initials: NH
authors.lastname: Liversedge
authors.forename: V A
authors.initials: VA
authors.lastname: Akande
authors.forename: R S
authors.initials: RS
authors.lastname: Mathur
authors.forename: J M
authors.initials: JM
authors.lastname: Jenkins
mesh_terms: D000328:Adult; D002064:Buserelin / Q000627:therapeutic use*; D016022:Case-Control Studies; D002452:Cell Count; D005260:Female; D005300:Fertility Agents, Female / Q000627:therapeutic use*; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000627:therapeutic use*; D006801:Humans; D009865:Oocytes; D009994:Osmolar Concentration; D010053:Ovary / Q000187:drug effects*; D010902:Pituitary Gland / Q000187:drug effects*; D011247:Pregnancy; D011379:Prognosis; D017526:Receptor, IGF Type 1 / Q000378:metabolism*; D020858:Tissue and Organ Harvesting
chemical_list: D005300:Fertility Agents, Female; D005640:Follicle Stimulating Hormone; D017526:Receptor, IGF Type 1; D002064:Buserelin