title: Use of an aromatase inhibitor in patients with polycystic ovary syndrome: a prospective randomized trial.
abstract: OBJECTIVE
  To compare the use of an aromatase inhibitor (letrozole) with the use of clomiphene citrate (CC).
  
  
  METHODS
  Prospective randomized study.
  
  
  METHODS
  An infertility clinic in a university hospital.
  
  
  METHODS
  Seventy-four consecutive infertile patients with polycystic ovary syndrome were recruited. Thirty-eight patients were randomized to the letrozole group (99 cycles), and the remaining patients were recruited to the CC group (95 cycles).
  
  
  METHODS
  The aromatase inhibitor letrozole (2.5 mg/d) and CC (100 mg/d) were administered orally on days 3-7 of menses.
  
  
  METHODS
  Number of follicles, endometrial thickness, E(2) levels on hCG day, and pregnancy rates among both groups.
  
  
  RESULTS
  Ovulation occurred in 65.7% (65/99) of letrozole cycles and in 74.7% (71/95) of CC cycles. The median (minimum-maximum) number of follicles sized >15 mm in diameter on the day of hCG administration were 1 (0-4) and 1 (0-5) in the letrozole and CC groups, respectively. On the day of hCG administration, median serum E(2) concentrations in the letrozole and CC groups were statistically significantly different: 189 pg/mL (18-1,581 pg/mL) and 386 pg/mL (27-6,190 pg/mL), respectively. The median serum E(2) concentrations per follicle sized >15 mm in diameter on the day of hCG also statistically significantly differed between the letrozole and CC groups: 160 pg/mL (18-808 pg/mL) and 281 pg/mL (27-2,615 pg/mL), respectively. The median endometrial thickness on the day of hCG did not significantly differ between the CC and letrozole groups; it was 8 mm. Pregnancy was achieved in nine cycles (9.1%) of the letrozole group and in seven cycles (7.4%) of the CC group, which also was not a statistically significant difference.
  
  
  CONCLUSIONS
  The aromatase inhibitor letrozole may be an acceptable alternative to CC as an ovulation-induction drug in patients with PCOS.
authors.affiliation: Zonguldak Karaelmas University Faculty of Medicine, Department of Obstetrics and Gynecology, Zonguldak, Turkey. ulkubayar@yahoo.com
authors.forename: Ulkü
authors.initials: U
authors.lastname: Bayar
authors.forename: Mustafa
authors.initials: M
authors.lastname: Basaran
authors.forename: Sibel
authors.initials: S
authors.lastname: Kiran
authors.forename: Ayhan
authors.initials: A
authors.lastname: Coskun
authors.forename: Sener
authors.initials: S
authors.lastname: Gezer
mesh_terms: D000284:Administration, Oral; D047072:Aromatase Inhibitors / Q000008:administration & dosage; D004311:Double-Blind Method; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000188:drug therapy* / Q000209:etiology; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000188:drug therapy*; D011247:Pregnancy; D011256:Pregnancy Outcome; D016896:Treatment Outcome
chemical_list: D047072:Aromatase Inhibitors; C042667:enkephalinamide-Leu, Tyr sulfate(1)-; D004743:Enkephalin, Leucine