Effects of clomiphene citrate on the endometrium of regularly cycling women

Fertil Steril. 2000 Feb;73(2):287-91. doi: 10.1016/s0015-0282(99)00509-9.


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 E2 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.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Clomiphene / pharmacology*
  • Endometrium / anatomy & histology
  • Endometrium / cytology
  • Endometrium / drug effects*
  • Estrogen Antagonists / pharmacology*
  • Female
  • Humans
  • Menstrual Cycle / drug effects*
  • Prospective Studies
  • Reference Values


  • Estrogen Antagonists
  • Clomiphene