COMPARISON BETWEEN NAFARELIN ACETATE AND D-TRP6-LHRH FOR TEMPORARY PITUITARY SUPPRESSION IN IN-VITRO FERTILIZATION (IVF) PATIENTS - A PROSPECTIVE CROSSOVER STUDY

Purpose: Nafarelin acetate is a new gonadotropin releasing (GnRH) agon ist analogue with unique potency, intranasal administration, and conve nient storage. Hence, nafarelin was considered as an alternative for t emporary pituitary suppression in patients under-going ovulation induc tion in IVF. A crossover treatment in a prospective study was performe d including 40 women with bilateral obstructed tubes and normal ovaria n function, treated in 80 ovulation induction cycles using the long pr otocol. Twenty patients used nafarelin acetate 600 mu g/daily in their first cycle and received D-Trp6-LHRH, 0.5 mg/daily, in their followin g cycle. The other 20 women used decapeptyl in their first cycle and r eceived nafarelin in the second. Results: Estradiol suppression was ac hieved by both D-Trp6-LHRH and nafarelin at equal time intervals. The average total number of ampoules (P = 0.0005) and the length of admini stration of hMG required for ovarian stimulation (P = 0.0002) and the time interval between GnRHa initiation to oocyte retrieval (P = 0.04) was significantly lower in nafarelin cycles. The number and the distri bution between large and small follicles as well as the average number of oocytes retrieved did not differ between the two GnRH analogues. C onclusion: Our results demonstrate that nafarelin acetate is comparabl e to D-Trp6-LHRH for temporary pituitary suppression used for controll ed ovarian stimulation in IVF patients. However, using nafarelin ovari an stimulation was achieved with fewer ampoules of hMG, administered f or a shorter period of time, thus with a lesser cost.