Oocyte donation: insights gleaned and future challenges.

With the first successful report of an IVF pregnancy achieved via donor oocytes in 1984, the applications of assisted reproductive technology (ART) were further expanded to include women unable to conceive with their own oocytes. Today, oocyte donation makes up an increasingly large percentage of all ART cycles worldwide. Oocyte donation presents several unique challenges to clinicians as two separate interests, those of the donor and those of the recipient, must be represented. These challenges include successful preparation of the endometrium in donor oocyte recipients, the synchronization of donor/recipient cycles, and the optimization of ovarian stimulation while maximizing donor safety. Facing these challenges has not only allowed for the creation of successful donor egg programs but has also provided insights into many aspects of ART. Much of what we know about the window of implantation, frozen ET procedures, triggering of oocyte maturation, and fertility preservation has been learned through experience and investigations with donor egg cycles. Not only has oocyte donation, through its optimization and wide use, provided new treatment opportunities for patients, it has also become a critical scientific tool to study many aspects of menstrual cycle dynamics and implantation. Concomitantly, with its increased efficiency, it has also raised several clinical and ethical challenges.