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Updated: Aug 9, 2026

Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
Letrozole vs. clomiphene citrate in patients with ovulatory infertility
Ulkü Bayar1, H Alper Tanriverdi, Aykut Barut
1Department of Obstetrics and Gynecology, University of Karaelmas, Zonguldak, Turkey. ulkubayar@yahoo.com
Objective:
To compare the effectiveness of letrozole and clomiphene citrate (CC) in ovulatory patients with borderline male factor infertility, early stage endometriosis, and unexplained infertility.
Design:
Prospective quasi-randomized trial.
Setting:
University infertility clinic.
Patient(S):
Forty-six consecutive patients with ovulatory infertility were recruited. Twenty-five patients (67 cycles) were given CC and 21 patients (52 cycles) were given letrozole. Both drugs were given orally on days 3-7 of menses.
Intervention(S):
Letrozole, CC, ovulation induction, IUI, timed intercourse.
Main Outcome Measure(S):
Number of follicles, endometrial thickness, and pregnancy rates.
Result(S):
The median serum E2 concentration on the day of hCG administration in the letrozole and CC groups were 191.5 pmol/L and 476.0 pmol/L, respectively. The median endometrial thickness on the day of hCG were 8 mm in both groups. Ovulation occurred in 81% (42/52) of the letrozole-treated and 85% (57/67) of the CC-treated patients. Pregnancy rate (PR) per cycle was 9% (5/52) in the letrozole group and 12% (8/67) in the CC group.
Conclusion(S):
Letrozole and CC have comparable effectiveness in ovulatory patients with borderline male factor infertility, early stage endometriosis, and unexplained infertility.
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