Impact of gonadotropin-releasing hormone antagonist addition on pregnancy rates in gonadotropin-stimulated intrauterine insemination cycles.

OBJECTIVES: The objective of the study is to evaluate the efficacy of gonadotropin-releasing hormone (GnRH) antagonist in improving clinical pregnancy rate in gonadotropin-stimulated intrauterine insemination (IUI) cycles in patients of unexplained infertility.

STUDY DESIGN: This was a prospective, randomized case-controlled study.

SETTINGS: The study was conducted in the infertility clinic of a tertiary care center.

MATERIALS AND METHODS: Four hundred twenty-seven women undergoing IUI following controlled ovarian stimulation with gonadotropins (recombinant follicle-stimulating hormone [r-FSH] 75 IU/day) were randomly divided into two groups. Women in Group I received GnRH antagonist (Cetrorelix 0.25 mg/day) in a multiple dose flexible protocol. Women in Group II received r-FSH alone. Ovulatory trigger was given with human chorionic gonadotropin 5000 IU when dominant follicle was ≥18 mm. IUI was performed within 44-48 h. Both groups received similar luteal phase support. Primary outcome measure was clinical pregnancy rate. The trial was powered to detect an absolute increase in clinical pregnancy rate by 13% from an assumed 20% clinical pregnancy rate in the control group, with an alpha error level of 0.05 and a beta error level of 0.20.

RESULTS: Clinical pregnancy rate in Groups I and II was 27.6% (n = 56) and 26.5% (n = 54), respectively (P=0.800). Ongoing pregnancy and multiple pregnancy rates were likewise similar between the groups.

CONCLUSIONS: Addition of GnRH antagonist to gonadotropin-stimulated IUI cycles results in no significant difference in clinical pregnancy rate.