The addition of GnRH antagonists in intrauterine insemination cycles: a pilot study.

AIM: This prospective study was designed to assess whether the use of GnRH antagonists can improve the success rate of controlled ovarian stimulation (COS) in in - trauterine insemination (IUI) treatments. PATIENTS AND METHODS: Eighty patients were divided into two groups: GnRH antagonist group (Group A, n=40) and control group (Group B, n=40). Patients in Group B underwent COS with recombinant Follicle Stimulating Hormone (r-FSH, 50-75 IU/d) only, while patients in Group A were ad - ministered r-FSH (50-75 IU/d) plus cetrorelix (0.25 mg/d, starting when ≥ 2 follicles ≥ 14 mm were de - tected on ultrasound scan). In both groups a sin - gle insemination was performed 36 hours after hu - man Chorionic Gonadotropin (hCG, 250 mcg) ad - ministration. The primary outcome was clinical Pregnancy Rate (PR). Secondary outcomes were ongoing PR, incidence of Premature Luteinization (PL), number of follicles with mean diameter ≥ 16 mm and between 11 and 15 mm on the day of hCG administration, miscarriage rate, cycle cancellation rate, total amount of r-FSH used and duration of treatment. Student's t test and Chi-square test were used ( p < .05 statistically significant). RESULTS: A total of 146 cycles were performed (Group A: n=72; Group B: n=74). A trend towards higher PR in Group A was detected, although it was not statistically significant (Clinical PR: 18.05% vs 10.81%). The number of follicles ≥ 16 mm was significantly increased in Group A. The incidence of both premature LH surge and prema - ture luteinization (PL) was significantly higher in Group B. No significant differences were found in the duration of the stimulation protocol, and in the total amount of r-FSH administered. CONCLUSIONS: The addition of GnRH antag - onist in COS/IUI protocol significantly increases the number of mature follicles. However, this multifollicular recruitment is not linked to a sig - nificantly higher PR .