Nafarelin acetate for pituitary down-regulation in in vitro fertilization. Comparison of two dosages.

The objective of this study was to evaluate the efficacy of intranasal (IN) nafarelin acetate (NA), 400 micrograms/d and 600 micrograms/d, in a luteal-phase-start, long protocol in women undergoing their first in vitro fertilization (IVF) cycle. A sequential comparison of 200 consecutive first IVF cycles, the study was performed in the Department of Gynaecology and Reproductive Medicine, University Hospital, London, Ontario, Canada. The participants were 200 first-cycle IVF patients who were regularly cycling--100 NA 400 micrograms IN followed by 100 NA 600 micrograms IN. Eighty-two percent of the NA 400 micrograms group were adequately suppressed after 11 days of treatment (serum estradiol < or = 150 pmol/L) as compared to 87% with NA 600 micrograms/d. These results compare favorably with those in a historical control group of 179 subjects receiving daily leuprolide acetate (LA), 0.5 mg subcutaneously, in their first cycle of IVF. The amount of human menopausal gonadotropin required for optimal follicular development was similar for the two NA groups. Clinical pregnancy rates were 13% per cycle and 21.7% per embryo transfer (ET) for NA 400 micrograms od and 19% per cycle and 30.1%/ET for NA 600 micrograms od (normal standard dose). No spontaneous luteinizing hormone (LH) surges occurred in any subject. Patient counseling and instruction time for NA use, which required nursing time, averaged five minutes per patient and an additional five minutes of video-viewing time. NA, 400 micrograms and 600 micrograms per day, appear to be acceptable alternate choices for pituitary down-regulation in a luteal-phase-start, long down-regulation protocol for IVF.(ABSTRACT TRUNCATED AT 250 WORDS)