“…From a literature review, 34 studies were published regarding the double stimulation approach in patients undergoing IVF treatment (Table 1). Among them, 23 studies used GnRH agonist trigger for final oocyte maturation in the first stimulation [3,4,5 ▪ ,7,8,10,11,14–23,24 ▪ ,25–29], six studies used hCG (3 rec-hCG and 2 u-hCG) [30–35], and five studies did not specifically distinguish the type of the trigger (GnRH-a ± hCG or hCG) [13,36–39]. GnRH agonist is the most common agent used for triggering and this tendency might depend on the putative negative effect exerted by the longer half-life of hCG on follicle growth during the subsequent LPS [18].…”