efficacy of low dose, long-acting gonadotropin releasing hormone analogues (gnrh-a) compared with daily injections of short-acting gnrh-a in art cycles

background: the retrieval of good quality oocytes that is accomplished with selection of the best induction ovulation protocol on the basis of patients condition, age and cause of infertility, is one of the most important aspects of art cycles. the objective was to evaluate the efficacy of low dose, long acting gnrh-a (decapeptyle) for pituitary desensitization and outcome of art compared to long protocol of short acting gnrh-a (busereline). materials and methods: in this randomized clinical trial that was performed at yazd ivf center, 60 patients with 61 cycles of art were included. patients with endometriosis or age > 40 were excluded in this study. using coh-et, patients were randomly divided into two groups. in group one, 30 patients received a single half dose of decapeptyle (1.87mg) in mid-luteal phase. in the other group, 31 patients received buserelin daily (0.5mg), starting from previous mid-luteal phase. this was reduced to 0.25mg from gonadotropin administration day and was continued until the day of hcg injection. in these groups, the number of oocytes, the fertilization, cleavage, pregnancy and cancellation rates were compared. results: in two groups, there was no case of cancellation due to premature lh surge. in group i, the mean number of gonadotropins was 27.5+4.2 ampoules while in the second group, it was 28.4±2.8 ampoules (p>0.05). 312 oocytes from group i and 294 oocytes from group ii were retrieved. oocyte quality in group ii was better than group i (84.3% vs 77.2%, p<0.05). in long-acting gnrh-a group fertilization rate was 81.9% versus 71.1%in group ii (p<0.01). however, embryo development in group i (85.6% vs 94.1%, p<0.05) was lower than group ii. although, pregnancy rate was 20% in group i which was higher than group ii (12.6%) but, there was no significant difference in cancellation, pregnancy rate and gonadotropins dose in two groups. conclusion: the low dose long acting gnrh-a is a useful method for pituitary suppression. low dose gnrh-a combined with gonadotropins permitted the retrieval of good quality oocytes and had no effect on oocytes. the fertilization and pregnancy rates with this method are acceptable and its cost and tolerance is valuable for patients.