GnRH antagonist in older IVF patients: Retrieval rates and clinical outcome

OBJECTIVE: To determine if the use of a midcycle GnRH antagonist provides better clinical outcomes and lower cancellation rates in in vitro fertilization (IVF). STUDY DESIGN: We examined all patients older than 40 years undergoing IVF-embryo transfer cycles between January 1999 and December 2000. Prior to June 2000, controlled ovarian stimulation in women ≥40 years was performed with follicle stimulating hormone (FSH)/human menopausal gonadotropin (hMG) only and no GnRH agonist or antagonist (group I). After June 2000, following the release of Ganirelix in the U.S., all women ≥40 years were stimulated with FSH/hMG + Ganirelix (group II). Outcomes of IVF cycles prior to Ganirelix were compared to results after its introduction. RESULTS: Cancellation rates were significantly lower in group II (16%) as compared to group I (67%) (P < .05). In patients with oocytes retrieved, group II had a significantly higher number of recovered oocytes (7.7 ± 0.8 vs. 5.3 ± 0.7 P < .05). However, the number of embryos transferred, cumulative embryo scores, implantation rates and ongoing pregnancy rates did not differ significantly between groups. CONCLUSION: Although our results are preliminary, the addition of GnRH antagonist avoids ovarian suppression at the start of controlled ovarian hyperstimulation and prevents the premature LH surge at midcycle. Thus, more patients attempting IVF undergo oocyte retrieval, although clinical outcomes may not necessarily be improved.