title: Does the addition of clomiphene citrate or letrazole to gonadotropin treatment enhance the oocyte yield in poor responders undergoing IVF?
abstract: OBJECTIVE
  To evaluate the effect of adjunctive letrazole or clomiphene in IVF stimulation protocols.
  
  
  METHODS
  A retrospective analysis of high dose GnRH antagonist IVF cycles (450-600 IU of gonadotropins) that have met poor responder criteria. Selected consecutive cycles in same patients differed solely in presence or absence of adjunctive clomiphene or letrazole.
  
  
  RESULTS
  Supplementation with clomiphene citrate in poor responders showed significant improvements (p < 0.05) in estradiol levels (1506 vs. 1044 pg/ml), number of dominant follicles (5.6 vs. 3.9), oocytes retrieved (5.2 vs. 3.4) and number of transferred embryos (1.7 vs. 1.1). It significantly improved biochemical pregnancy rates (18.1% vs. 5.9%) while reducing cycle cancellations (11.7% vs. 32.6%). Letrozole supplementation showed similar effects.
  
  
  CONCLUSIONS
  Both Clomiphene and Letrazole performed similarly and showed significant effects. However, despite increasing oocyte yield and embryo transfer rates, the overall clinical and live birth rate in this population remained low and showed no measurable increase.
authors: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY 10032, USA. vpj2102@columbia.edu
authors: Vuk P
authors: VP
authors: Jovanovic
authors: Daniel H
authors: DH
authors: Kort
authors: Michael M
authors: MM
authors: Guarnaccia
authors: Mark V
authors: MV
authors: Sauer
authors: Rogerio A
authors: RA
authors: Lobo
mesh_terms: D000328:Adult; D001723:Birth Rate; D002996:Clomiphene / Q000008:administration & dosage*; D004624:Embryo Transfer / Q000379:methods*; D004958:Estradiol / Q000097:blood; D004965:Estrogen Antagonists / Q000008:administration & dosage*; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000097:blood; D006062:Gonadotropins / Q000008:administration & dosage*; D006727:Hormone Antagonists / Q000494:pharmacology; D006801:Humans; D000077289:Letrozole; D009570:Nitriles / Q000008:administration & dosage*; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development*; D006080:Ovarian Follicle / Q000187:drug effects; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D014230:Triazoles / Q000008:administration & dosage*
chemical_list: D004965:Estrogen Antagonists; D006062:Gonadotropins; D006727:Hormone Antagonists; D009570:Nitriles; D014230:Triazoles; D002996:Clomiphene; D004958:Estradiol; D000077289:Letrozole; D005640:Follicle Stimulating Hormone