Effect of antiprogesterone mifepristone followed by misoprostol on circulating leptin in early pregnancy

Background. To study the role of progesterone (P4) in the regulation of circulating leptin in early human pregnancy, we measured the levels of leptin before and after administration of the antiprogestin mifepristone, followed by misoprostol in early pregnancy. Methods. Thirty-four women requesting termination of pregnancy, with ≤63 days of amenorrhea, received 200 mg of mifepristone on day 0, followed by either oral or vaginal administration of 0.8 mg of misoprostol on day 2. Five serial serum samples were assayed for leptin, human chorionic gonadotrophin (hCG), P4, estradiol (E2), cortisol, and mifepristone. Results. Circulating leptin concentrations decreased by 8.7 ± 29.7% (mean ± standard deviation) ( p < 0.05) following the ingestion of mifepristone. After misoprostol administration on day 2, a decrease of 12.6 ± 17.0% ( p < 0.05) was followed by a rebound on day 3 to 87.6 ± 25.7% of the pretreatment values. Two weeks after mifepristone, leptin levels had declined by 25.4 ± 30.4%. In contrast, E2, P4...