Shruti Parikh and Christophe Blockeel
Recent approaches in IVF are trending towards more physiological and patient friendly stimulation cycles, with reduction in cost and stress associated with ovarian stimulation. Delaying onset of stimulation from day 2 to day 5 in a GnRH antagonist protocol is a novel approach which helps maintain a more physiological hormonal milieu. The present review compares the follicular growth patterns and endocrine profiles in women undergoing delayed onset versus the conventional day 2 start of ovarian stimulation.