Effects of clomiphene citrate on the endometrium of regularly cycling women

Objective: To study the effects of clomiphene citrate (CC) on the endometrium of regularly cycling women. Design: Prospective, controlled study. Setting: Department of Obstetrics and Gynaecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. Patient(s): Thirty healthy, regularly cycling, female volunteers. Intervention(s): All volunteers were studied for two consecutive cycles, one control cycle and one CC-treated cycle. Clomiphene citrate (100 mg/d) was given on days 3-7 of the CC-treated cycles. Ultrasonography was performed daily to assess ovulation. Ultrasonography and endometrial biopsy were performed, and blood samples were obtained for determination of E-2 and progesterone levels 7 days after ovulation in both the control and CC-treated cycles. Main Outcome Measure(s): Histologic dating, morphometric analysis, and ultrasonographic appearance and thickness of the endometrium. Result(s): Histologic dating and ultrasonographic appearance and thickness of the endometrium were similar in the control and CC-treated cycles, but morphometric parameters were different. The number of glands per square millimeter and the mean diameter of the glands were lower in the CC-treated cycles than in the control cycles, but the number of vacuolated cells per 1,000 glandular cells was higher. Conclusion(s): Clomiphene citrate has effects on the endometrium of regularly cycling women, as demonstrated by a reduction in glandular density and an increase in the number of vacuolated cells. (Fertil Steril(R) 2000;73:287-91. (C) 2000 by American Society for Reproductive Medicine.)