Clomiphene citrate does not adversely affect endometrial leukemia inhibitory factor levels.

The aim of this study was to compare endometrial leukemia inhibitory factor (LIF) levels in spontaneous and clomiphene citrate (CC)-induced cycles of patients with unexplained infertility. The patients were followed in two consecutive cycles. Endometrial samples were obtained 7 days after ultrasonographic evidence that ovulation has occurred during the spontaneous cycle, then the patients were induced with CC from day 5 to day 9 during the subsequent cycle with 50 mg/day, and ovulation monitoring and endometrial biopsy were performed in the same manner. The samples were obtained using a Pipelle biopsy device without using local anesthesia, and kept in formaldehyde solution until the day of measurement. Then they were homogenized in phosphate buffered distilled water, and LIF levels were detected in the homogenized fluid by ELISA method. Endometrial LIF levels were 470 +/- 52 and 501 +/- 45 pg/1 gram wet tissue in spontaneous and CC-induced cycles respectively, revealing no significant difference. Ovulation induction with CC did not adversely affect endometrial LIF levels.