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

Int J Gynaecol Obstet. 2003 Jun;81(3):287-92. doi: 10.1016/s0020-7292(02)00404-6.


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.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Clomiphene / pharmacology*
  • Clomiphene / therapeutic use*
  • Endometrium / diagnostic imaging*
  • Endometrium / drug effects*
  • Endometrium / physiopathology
  • Estradiol / blood*
  • Female
  • Fertility Agents, Female / pharmacology*
  • Fertility Agents, Female / therapeutic use*
  • Fertilization / drug effects
  • Fertilization / physiology
  • Humans
  • Infertility, Female / blood
  • Infertility, Female / diagnostic imaging
  • Infertility, Female / drug therapy*
  • Male
  • Menstrual Cycle / drug effects*
  • Menstrual Cycle / physiology
  • Ovarian Follicle / diagnostic imaging
  • Ovarian Follicle / drug effects*
  • Ovarian Follicle / growth & development*
  • Ovulation Induction
  • Pregnancy
  • Pregnancy Rate
  • Ultrasonography


  • Fertility Agents, Female
  • Clomiphene
  • Estradiol