M F M Mitwally1, R F Casper. 1. Samuel Lunenfeld Research Institute and Mount Sinai Hospital, Reproductive Sciences Division, Department of Obstetrics & Gynecology, University of Toronto, Toronto, Canada.
Abstract
BACKGROUND: Adding clomiphene citrate (CC) to FSH for controlled ovarian stimulation (COS) decreases FSH dose required for optimum stimulation. However, because of its anti-estrogenic effects, CC may be associated with lower pregnancy rates offsetting the FSH-dose reduction benefit. Previously, we reported the success of aromatase inhibition in inducing ovulation without antiestrogenic effects. METHODS: A prospective pilot study that included women with unexplained infertility undergoing COS and intrauterine insemination. Thirty-six women received the aromatase inhibitor letrozole + FSH, 18 women received CC + FSH and 56 women received FSH only. Each woman received one treatment regimen in one treatment cycle. All patients were given recombinant or highly purified FSH (50-150 IU/day) starting on day 3 to 7 until day of hCG. RESULTS: The FSH dose needed was significantly lower in letrozole + FSH and CC + FSH groups compared with FSH-only without a difference in number of follicles >1.8 cm. Pregnancy rate was 19.1% in the letrozole + FSH group, 10.5% in the CC + FSH group and 18.7% in the FSH-only group. Both pregnancy rate and endometrial thickness were significantly lower in CC + FSH group compared with the other two groups. Estradiol (E2) levels were significantly lower in the letrozole + FSH group compared with the other two groups. CONCLUSIONS: Similar to CC, aromatase inhibition with letrozole reduces FSH dose required for COS without the undesirable antiestrogenic effects sometimes seen with CC.
BACKGROUND: Adding clomiphene citrate (CC) to FSH for controlled ovarian stimulation (COS) decreases FSH dose required for optimum stimulation. However, because of its anti-estrogenic effects, CC may be associated with lower pregnancy rates offsetting the FSH-dose reduction benefit. Previously, we reported the success of aromatase inhibition in inducing ovulation without antiestrogenic effects. METHODS: A prospective pilot study that included women with unexplained infertility undergoing COS and intrauterine insemination. Thirty-six women received the aromatase inhibitor letrozole + FSH, 18 women received CC + FSH and 56 women received FSH only. Each woman received one treatment regimen in one treatment cycle. All patients were given recombinant or highly purified FSH (50-150 IU/day) starting on day 3 to 7 until day of hCG. RESULTS: The FSH dose needed was significantly lower in letrozole + FSH and CC + FSH groups compared with FSH-only without a difference in number of follicles >1.8 cm. Pregnancy rate was 19.1% in the letrozole + FSH group, 10.5% in the CC + FSH group and 18.7% in the FSH-only group. Both pregnancy rate and endometrial thickness were significantly lower in CC + FSH group compared with the other two groups. Estradiol (E2) levels were significantly lower in the letrozole + FSH group compared with the other two groups. CONCLUSIONS: Similar to CC, aromatase inhibition with letrozole reduces FSH dose required for COS without the undesirable antiestrogenic effects sometimes seen with CC.
Authors: Michael P Diamond; Richard S Legro; Christos Coutifaris; Ruben Alvero; Randal D Robinson; Peter Casson; Gregory M Christman; Joel Ager; Hao Huang; Karl R Hansen; Valerie Baker; Rebecca Usadi; Aimee Seungdamrong; G Wright Bates; R Mitchell Rosen; Daniel Haisenleder; Stephen A Krawetz; Kurt Barnhart; J C Trussell; Dana Ohl; Yufeng Jin; Nanette Santoro; Esther Eisenberg; Heping Zhang Journal: N Engl J Med Date: 2015-09-24 Impact factor: 91.245
Authors: Michael P Diamond; Richard S Legro; Christos Coutifaris; Ruben Alvero; Randal D Robinson; Peter Casson; Gregory M Christman; Joel Ager; Hao Huang; Karl R Hansen; Valerie Baker; Rebecca Usadi; Aimee Seungdamrong; G Wright Bates; R Mitchell Rosen; Daniel Haisonleder; Stephen A Krawetz; Kurt Barnhart; J C Trussell; Yufeng Jin; Nanette Santoro; Esther Eisenberg; Heping Zhang Journal: Fertil Steril Date: 2015-02-20 Impact factor: 7.329
Authors: Michael P Diamond; Mohamed Mitwally; Robert Casper; Joel Ager; Richard S Legro; Robert Brzyski; Peter Casson; Esther Eisenberg; Heping Zhang Journal: Contemp Clin Trials Date: 2011-07-20 Impact factor: 2.226