International Journal of Reproductive Medicine
Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences of Yazd
Vol. 2, No. 2, 2004, pp. 78-81
Bioline Code: rm04016
Full paper language: English
Document type: Research Article
Document available free of charge
International Journal of Reproductive Medicine, Vol. 2, No. 2, 2004, pp. 78-81
© Copyright 2004 - Iranian Journal of Reproductive Medicine
The Effect of Letrozole in Induction of Ovulation in Clomiphene Resistant Patients|
Davar, Robab & Aflatoonian, Abbas
In patients with anovulatory infertility the first choice of treatment for ovulation induction is an antiestrogen, most commonly clomiphene citrate (CC). However, 20-25% of the women are resistant to CC and do not ovulate perhaps due to antiestrogenic mechanism of the CC action, which involves long-lasting estrogen receptor (ER) depletion. Objective: The objective of the study was to mimic the action of CC without depletion of ERs by the administration of an aromatase inhibitor letrozole in a selected group of Poly Cystic Ovary (PCO) patients who demonstrated failure to ovulate after treatment with CC.
Materials and Methods:
20 patients with anovulation due to polycystic ovary syndrome (PCOS), who had previously inadequately responded to CC were selected for study. The aromatase inhibitor letrozole was administered orally in a dose of 2.5 mg on days 3-7 of the menstrual cycle. Then, occurrence of ovulation, endometrial thickness, and pregnancy rates were determined.
Only one patient had one dominant follicle (1.8 cm diameter) on day 14 of the cycle (estradiol = 200 pg/ml). IUI was done; however, no pregnancy took place. In the remaining cases, several sonographies were done between days 9 to 15 of the cycle; however, all cycles were cancelled due to absence of a dominant follicle (>1.4 cm).
Our study did not confirm the favorable effect of letrozole for induction of ovulation in patients with clomiphene resistant PCO.
Letrozole, Clomiphene failure, PCOS
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