title: Extended letrozole therapy for ovulation induction in clomiphene-resistant women with polycystic ovary syndrome: a novel protocol.
abstract: OBJECTIVE
  To evaluate the outcome of long letrozole therapy for induction of ovulation in patients with clomiphene-resistant polycystic ovary syndrome (PCOS).
  
  
  METHODS
  Prospective randomized controlled study.
  
  
  METHODS
  University teaching hospital and a private practice.
  
  
  METHODS
  The study comprised 218 patients with clomiphene-resistant PCOS.
  
  
  METHODS
  Patients were randomly allocated to treatment with either long letrozole therapy (n = 108; 219 cycles) or short letrozole therapy (n = 110; 225 cycles).
  
  
  METHODS
  Number of growing and mature follicles, serum E(2) (pg/mL), serum P (ng/mL), endometrial thickness, occurrence of pregnancy and miscarriage.
  
  
  RESULTS
  The number of ovulating patients was greater in the long letrozole group (65.7% vs. 61.8%), but without statistical differences. The total numbers of follicles during stimulation was significantly greater in the long letrozole group (6.7 +/- 0.3 vs. 3.9 +/- 0.4). The numbers of follicles > or =14 mm and > or =18 mm were significantly greater in the long letrozole group. There was no significant difference in the pretreatment endometrial thickness or endometrial thickness at the time of hCG administration between the two groups. Pregnancy occurred in 28 of 225 cycles in the short group (12.4%) and 38 of 219 cycles (17.4%) in the long letrozole group, and the difference was statistically significant.
  
  
  CONCLUSIONS
  The long letrozole protocol (10 days) can produce more mature follicles and subsequently more pregnancies than the short letrozole therapy (5 days).
authors.affiliation: Department of Obstetrics and Gynecology, Mansoura University Hospitals, Mansoura, Egypt. ambadawy@yahoo.com
authors.forename: Ahmed
authors.initials: A
authors.lastname: Badawy
authors.forename: Alaa
authors.initials: A
authors.lastname: Mosbah
authors.forename: Ayman
authors.initials: A
authors.lastname: Tharwat
authors.forename: Mohamed
authors.initials: M
authors.lastname: Eid
mesh_terms: D000328:Adult; D000858:Anovulation / Q000453:epidemiology; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D002996:Clomiphene / Q000627:therapeutic use*; D004351:Drug Resistance; D004965:Estrogen Antagonists / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D017588:Hyperandrogenism / Q000453:epidemiology; D000077289:Letrozole; D009570:Nitriles / Q000627:therapeutic use*; D006080:Ovarian Follicle / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D010062:Ovulation Induction / Q000379:methods*; D010298:Parity; D011085:Polycystic Ovary Syndrome / Q000188:drug therapy*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome; D014230:Triazoles / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D047072:Aromatase Inhibitors; D004965:Estrogen Antagonists; D009570:Nitriles; D014230:Triazoles; D002996:Clomiphene; D000077289:Letrozole