Effectiveness of low dose of gonadotropin releasing hormone agonist on hormonal flare-up

PURPOSE: The hormonal response (flare-up) following administration of a standard dose (100 micrograms) or a low dose (25 micrograms) of gonadotropin releasing hormone agonist (GnRH-a) (Triptorelin) was compared in patients prior to an in vitro fertilization (IVF) cycle and during the early follicular phase of a short-term IVF protocol. METHODS: The gonadotroph (FSH, LH) and steroid [estradiol (E2) and progesterone (P)] flare-up was studied on two consecutive cycles in 30 normo-ovulatory women. Patients were randomized to receive either 25 or 100 micrograms of triptorelin for three days at the beginning of the first cycle. Then doses were switched according to a crossing over design in the second cycle. RESULTS: No significant difference in the magnitude of FSH and E2 release could be observed following administration of the two doses of agonist whereas maximal plasma LH level was significantly reduced after injection of 25 micrograms of triptorelin. CONCLUSIONS: As compared to a standard dose, using a low dose of GnRH-a induces an hormonal flare-up which seems adequate for an optimal follicular recruitment.