GnRH-agonist versus GnRH-antagonist IVF cycles: is the reproductive outcome affected by the incidence of progesterone elevation on the day of HCG triggering? A randomized prospective study†. - Papanikolaou, E.G.; Pados, G.; Grimbizis, G.; Bili, E.; Kyriazi, L.; Polyzos, N.P.; Humaidan, P.; Tournaye, H.; Tarlatzis, B. (Human Reproduction, 2012)