Figure 1From: GnRH agonist versus GnRH antagonist in in vitro fertilization and embryo transfer (IVF/ET)GnRH agonist protocols. Long Protocol: GnRH agonist 0.1 mg starting in follicular phase or luteal phase (Cycle Day 21) of the previuos cycle until hCG administration . Short Protocol: GnRH agonist 0.1 mg starting on day 1 or 3 of stimulation until hCG administration. Ultrashort Protocol: GnRH agonist 0.1 mg administered on day 2–4 of stimulation.Back to article page