Comparative Analysis of Effectiveness of Clomiphene Citrate and Letrozole Combined with Low Dose Human Menopausal Gonadotropin for Controlled Ovarian Stimulation in Intrauterine Insemination Cycles

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Padmalaya Thakur
Sujata Pradhan


Objective: To compare the efficacy of clomiphene citrate and letrozole in combination with low dose human menopausal gonadotropin for controlled ovarian stimulation in intrauterine insemination (IUI) cycles.
Methods: During January-2018 to December-2019 for intending 496 IUI cycles, controlled ovarian stimulation was performed with either clomiphene or letrozole combined with human menopausal gonadotropin (hMG), in two arms:  subjects in one arm (Group A) were with clomiphene and hMG in 222 cycles; those in the second arm (Group B) were with letrozole and hMG in 274 cycles. Pregnancy rate and clinical pregnancy rate of both groups were considered as the primary outcomes.
Results: Patient characteristics like female age, indications for IUI, type of IUI, endometrial thickness and total motile fraction (TMF) of spermatozoa of male partners were seen similar in both groups. The letrozole-hMG group (Group B) had significantly higher numbers of cycles with single dominant follicle (P=0.01) and human chorionic gonadotropin (hCG) was more frequently used as the ovulation trigger (P=0.03). Pregnancy rate (18.5% vs. 15.3%, P=0.35) and clinical pregnancy rate (18.5% vs. 15.3%, P=0.35) were similar in groups A and B, respectively.
Conclusion: Clomiphene citrate and letrozole combined with low dose human menopausal gonadotropin were equally effective for controlled ovarian stimulation in IUI cycles.


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Thakur, P., & Pradhan, S. (2021). Comparative Analysis of Effectiveness of Clomiphene Citrate and Letrozole Combined with Low Dose Human Menopausal Gonadotropin for Controlled Ovarian Stimulation in Intrauterine Insemination Cycles. Siriraj Medical Journal, 73(3), 198–203.
Original Article


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