A prospective randomized comparison of two gonadotrophin-releasing hormone agonists, nafarelin acetate and buserelin acetate, in in-vitro fertilization-embryo transfer.

We tested the efficacy of a new gonadotrophin-releasing hormone agonist (GnRHa), nafarelin acetate, in in-vitro fertilization (IVF), and compared the results with those of another widely used GnRHa, buserelin acetate; both were in the form of nasal spray. Therapy was used in a long protocol in the luteal phase in two groups of women with similar aetiology of infertility. There was no significant difference in patient response, measured by cycle cancellation, number of oocytes retrieved, fertilization rate and cleavage rate. Pregnancy rates were similar in nafarelin acetate and buserelin acetate treated women, namely 22% and 24% pregnancies per cycle, and 28.8% and 32.1% pregnancies per transfer, respectively. Side-effects were few and comparable in both groups. The only difference noted was that women receiving nafarelin acetate required significantly fewer ampoules of human menopausal gonadotrophin, making a significant difference in the expense involved. We conclude that on the basis of our experience, nafarelin acetate is an efficient and safe gonadotrophin-releasing hormone agonist, effective in IVF therapy.