Follicular growth, endometrial thickness, and serum estradiol levels in spontaneous and clomiphene citrate-induced cycles

Objectives: To evaluate follicular growth, endometrial thickness, and serum estradiol levels in spontaneous cycles and cycles induced by clomiphene citrate (CC). Methods: A 2-year prospective study of spontaneous cycle followed by a CC-induced cycle to compare paired data. Twenty couples with unexplained infertility were recruited from the Infertility Clinic of the Jawaharlal Institute of Postgraduate Medical Education and Research. An oral dose of 150 mg of CC was administered on days 5 through 9 of the CC-induced cycle. Each woman was evaluated using transvaginal sonography and serum estradiol level estimation from day 10 of the menstrual cycle until ovulation. Results were analyzed using the paired t-test. Results: The leading follicular diameter was significantly larger, endometrial thickness was significantly decreased, and serum estradiol levels were significantly higher in the follicular phase of CC-induced cycles. Conclusions: Clomiphene citrate-induced cycles showed different follicular, endometrial growth patterns, and serum estradiol levels compared with spontaneous cycles. (C) 2002 International Federation of Gynecology and Obstetrics. Published by Elsevier Science Ireland Ltd. All rights reserved.