Clinical experience with an ovarian stimulation protocol for intrauterine insemination adopting a gonadotropin releasing hormone antagonist at low dose

Studies testing the effectiveness of GnRH antagonists in controlled ovarian stimulation (COS) for intrauterine insemination (IUI) have provided controversial results. The present study was undertaken to evaluate, whether the use of a half of the conventional dose of the GnRH antagonist cetrorelix can be effective in increasing the successful rate of IUI cycles. Patients started COS with human menopausal gonadotropin (hMG) on day three of the menstrual cycle. Cetrorelix was started when at least one follicle of ≥14 mm, was detected at the ultrasound scan, according to the flexible multiple daily dose protocol, and continued until the trigger day with recombinant hCG. Patients adopting GnRH antagonist at low dose had a pregnancy rate (21.7%) that was significantly higher (p < 0.05) in comparison to women receiving hMG only (8.7%). These results suggest that adding a reduced dose of GnRH antagonist to the COS for IUI cycles significantly improves the outcome of the procedure.