Histology of midluteal corpus luteum and endometrium from clomiphene citrate-induced cycles.

Objective: To determine the histologic development of midluteal corpus luteum (CL) and endometrium in normal fertile women after induction of ovulation with clomiphene citrate (CC). DESIGN, PATIENTS, INTERVENTIONS: Twelve normally cycling women planning to undergo an elective tubal ligation were treated with 50 to 150 mg of CC daily on days 5 through 9 of the cycle. Luteectomy and endometrial biopsy were performed simultaneously 7 days after the urinary luteinizing hormone surge.

Results: Because polyovulation occurred in 10 of the 12 women, 22 CL and 12 endometrial biopsies were studied. Ten women had luteal and endometrial histology that were within 2 days of the ovulation to biopsy interval. The 2 remaining women had endometrial histology that lagged 3 days behind the chronological postovulatory date. In these women, out-of-phase endometrium occurred despite polyovulatory cycles in which two and three histologically normal CL lutea were present and associated with elevated progesterone concentrations.

Conclusions: In CC-induced ovulatory cycles: (1) midluteal CL histology is normal and (2) apparently out-of-phase preimplantation endometrium occurs in midluteal phase.