title: Letrozole and gonadotropins versus luteal estradiol and gonadotropin-releasing hormone antagonist protocol in women with a prior low response to ovarian stimulation.
abstract: OBJECTIVE
  To compare in vitro fertilization outcomes after ovarian stimulation using letrozole/antagonist (LA) versus luteal-phase estradiol (E(2))/gonadotropin-releasing hormone (GnRH) antagonist (LPG) in poor responders.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Academic center.
  
  
  METHODS
  Ninety nine women with ≥2 prior cycles, at a starting dose of ≥300 IU gonadotropins, who yielded fewer than five oocytes or a prior cycle cancellation.
  
  
  METHODS
  In the LPG group (n=52), transdermal E2 initiated every other day starting day 10 after the luteinizing hormone (LH) surge; one day 11, patients began daily administration of antagonist for 3 consecutive days, with gonadotropins started on the second day of menstruation. In the LA group (n=47), letrozole 5 mg/day initiated on the second day of spontaneous menstruation for 5 days then gonadotropins added on day 5; for both groups a flexible antagonist protocol was used.
  
  
  METHODS
  Ongoing pregnancy, number of oocytes retrieved, and cancellation rate.
  
  
  RESULTS
  The total dose of gonadotropins administered and E2 levels on day of hCG administration were statistically significantly lower with the LA protocol. The number of oocytes retrieved (6.1±3.0 vs. 7.9±4.8), number of transferred embryos (2.2±1.0 vs. 2.4±1.4), and cancellation rate (55.3% vs. 36.5%) were similar in both groups. Ongoing pregnancy rates per transfer (40% vs. 21.2%) and per initiated cycle (19.1% vs. 13.5%) were similar in the LA and LPG groups, respectively.
  
  
  CONCLUSIONS
  Aromatase inhibitor regimens can be a feasible alternative to the LPG protocol in recurrent low ovarian response.
authors.affiliation: Center for Advanced Reproductive Services, University of Connecticut Health Center, Department of Obstetrics and Gynecology, University of Connecticut, Farmington, Connecticut 06030-6224, USA.
authors.forename: Alyaa
authors.initials: A
authors.lastname: Elassar
authors.forename: Lawrence
authors.initials: L
authors.lastname: Engmann
authors.forename: John
authors.initials: J
authors.lastname: Nulsen
authors.forename: Claudio
authors.initials: C
authors.lastname: Benadiva
mesh_terms: D000328:Adult; D047072:Aromatase Inhibitors / Q000008:administration & dosage*; D016009:Chi-Square Distribution; D003237:Connecticut; D004334:Drug Administration Schedule; D004958:Estradiol / Q000008:administration & dosage*; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage*; D005307:Fertilization in Vitro; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors*; D006062:Gonadotropins / Q000008:administration & dosage*; D006727:Hormone Antagonists / Q000008:administration & dosage*; D006801:Humans; D000077289:Letrozole; D008183:Luteal Phase; D009570:Nitriles / Q000008:administration & dosage*; D054315:Oocyte Retrieval; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014230:Triazoles / Q000008:administration & dosage*
chemical_list: D047072:Aromatase Inhibitors; D005300:Fertility Agents, Female; D006062:Gonadotropins; D006727:Hormone Antagonists; D009570:Nitriles; D014230:Triazoles; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D000077289:Letrozole