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 mu g) or a low dose (25 mu g) 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 (E-2) 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 mu g 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 E-2 release could be observed following administration of the two doses of agonist whereas maximal plasma LH level was significantly reduced after injection of 25 mu g of triptorelin. Conclusions: As compared to a standard dose, using a low close of GnRH-a induces an hormonal flare-up which seems adequate for an optimal follicular recruitment.