During ovum pick-up, we aspirate all the FF and throw it away after ovum retrieval. This fluid normally enters the fallopian tubes while picking the ovum during ovulation in natural cycles and it reaches the uterine cavity as well and several studies suggested that it might have a crucial role in modifying uterine receptivity preparing the endometrium for the fertilized ovum arriving after 3 days as the TGF controls apoptosis, the IGF improves endometrial thickness and the immunosuppressive activity of the FF paves the way for the embryo to implant in the uterine cavity (4,5).