title: Management of poor responders: can outcomes be improved with a novel gonadotropin-releasing hormone antagonist/letrozole protocol?
abstract: OBJECTIVE
  To compare the efficacy of a microdose GnRH agonist flare (ML) with a GnRH antagonist/letrozole (AL) protocol before IVF-ET in poor responders.
  
  
  METHODS
  Prospective controlled trial.
  
  
  METHODS
  Private assisted reproductive technology center.
  
  
  METHODS
  Five hundred thirty-four infertile women classified as past or potential poor responders based on clinic-specific criteria.
  
  
  METHODS
  Poor responders were prospectively assigned to an ML or AL protocol in a 2:1 ratio, respectively.
  
  
  METHODS
  Results of controlled ovarian hyperstimulation and implantation and ongoing pregnancy rates.
  
  
  RESULTS
  Patient characteristics were similar between the two protocol groups. There were no significant differences in mean age, number of oocytes, fertilization rates, number of embryos transferred, or embryo score. Peak E(2) levels were significantly lower in the AL group. Ongoing pregnancy rates were significantly higher in the ML group (52% vs. 37%). Trends toward increased implantation and lower cancellation rates were also noted, but these did not reach statistical significance.
  
  
  CONCLUSIONS
  Quantitative results of stimulation between the ML and AL protocols were equivalent with the exception of peak E(2) levels. However, the higher ongoing pregnancy rates and trend toward superior implantation rates would suggest that ML represents a preferred approach for the poor responder. An increased sample size would be necessary to verify these findings.
authors.affiliation: Colorado Center for Reproductive Medicine, Englewood, Colorado, USA. bschoolcraft@colocrm.com
authors.forename: William B
authors.initials: WB
authors.lastname: Schoolcraft
authors.forename: Eric S
authors.initials: ES
authors.lastname: Surrey
authors.forename: Debra A
authors.initials: DA
authors.lastname: Minjarez
authors.forename: John M
authors.initials: JM
authors.lastname: Stevens
authors.forename: David K
authors.initials: DK
authors.lastname: Gardner
mesh_terms: D000328:Adult; D047072:Aromatase Inhibitors / Q000008:administration & dosage*; D006063:Chorionic Gonadotropin / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D046149:Embryo Culture Techniques; D010064:Embryo Implantation / Q000187:drug effects; D004624:Embryo Transfer; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage*; D005306:Fertilization / Q000187:drug effects; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists / Q000037:antagonists & inhibitors; D006801:Humans; D007247:Infertility, Female / Q000188:drug therapy / Q000628:therapy*; D000077289:Letrozole; D016729:Leuprolide / Q000008:administration & dosage*; D009570:Nitriles / Q000008:administration & dosage*; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D013997:Time Factors; D017211:Treatment Failure; D016896:Treatment Outcome; D014230:Triazoles / Q000008:administration & dosage*
chemical_list: D047072:Aromatase Inhibitors; D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; D009570:Nitriles; D014230:Triazoles; D007987:Gonadotropin-Releasing Hormone; D000077289:Letrozole; D005640:Follicle Stimulating Hormone; D016729:Leuprolide