title: Hormonal profile and endometrial morphology in letrozole-controlled ovarian hyperstimulation in ovulatory infertile patients.
abstract: OBJECTIVE
  To evaluate the clinical response and endometrial morphology during the implantation window on ovarian hyperstimulation with the aromatase inhibitor letrozole in infertile ovulatory women.
  
  
  METHODS
  Prospective trial in infertile patients.
  
  
  METHODS
  Tertiary care hospital.
  
  
  METHODS
  Eight ovulatory infertile patient candidates for ovarian superovulation.
  
  
  METHODS
  Subjects were monitored in one control cycle. In the next cycle, they received letrozole 5.0 mg daily on days 3 through 7 after menses.
  
  
  METHODS
  Number of ovulatory follicles; dominant follicle diameter; endometrial thickness; hormonal profile of FSH, LH, E(2), A, T, and P; endometrial histological dating; and pinopode formation assessed by scanning electron microscopy.
  
  
  RESULTS
  Cycles stimulated with letrozole resulted in more ovulatory follicles than did natural cycles (mean +/- SD 2.0 +/- 0.9 vs. 1.0 +/- 0.0), which attained a greater preovulatory diameter (mean +/- SD 23.8 +/- 2.7 vs. 19.3 +/- 2.1 mm), with similar endometrial thickness at midcycle compared with spontaneous cycles. Endocrine profile of medicated cycles was characterized on day 7 by increased levels of LH (5.9 +/- 0.8 vs. 3.5 +/- 0.4 IU/mL), reduced E(2) (98.4 +/- 11.4 vs. 161.5 +/- 14.7 pmol/L), and elevated androgens. Preovulatory and midsecretory E(2) were similar to spontaneous cycle, and P levels during midluteal phase were significantly elevated (44.2 +/- 4.6 vs. 27.7 +/- 4.6 pmol/L). Endometrial morphology during the implantation window in letrozole-stimulated cycles was characterized by in-phase histological dating and pinopode expression on scanning electron microscopy.
  
  
  CONCLUSIONS
  Letrozole induces moderate ovarian hyperstimulation in ovulatory infertile patients with E(2) levels similar to spontaneous cycles and higher midluteal P, leading to both a normal endometrial histology and development of pinopodes, considered to be relevant markers of endometrial receptivity.
authors.affiliation: Institute of Maternal and Child Research, School of Medicine, University of Chile, Santiago, Chile. acortinez@ns.hospital.uchile.cl
authors.forename: Armando
authors.initials: A
authors.lastname: Cortínez
authors.forename: Iara
authors.initials: I
authors.lastname: De Carvalho
authors.forename: David
authors.initials: D
authors.lastname: Vantman
authors.forename: Fernando
authors.initials: F
authors.lastname: Gabler
authors.forename: Germán
authors.initials: G
authors.lastname: Iñiguez
authors.forename: Margarita
authors.initials: M
authors.lastname: Vega
mesh_terms: D000328:Adult; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D004717:Endometrium / Q000473:pathology*; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D000077289:Letrozole; D009570:Nitriles / Q000627:therapeutic use*; D010062:Ovulation Induction; D011374:Progesterone / Q000097:blood; D011446:Prospective Studies; D014230:Triazoles / Q000627:therapeutic use*
chemical_list: D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D011374:Progesterone; D004958:Estradiol; D000077289:Letrozole