Fig. 1From: Individualized luteal phase support after fresh embryo transfer: unanswered questions, a reviewOptimal initiation and duration of LPS. The optimal initiation of LPS should be between 24 and 72Â h after oocyte retrieval; the duration of LPS should at least last to pregnancy test is positive. OPU oocyte pick-up, ET embryo transfer, LPS luteal phase supportBack to article page