The egg-sharing model for human therapeutic cloning research: managing donor selection criteria, the proportion of shared oocytes allocated to research, and amount of financial subsidy given to the donor.

Recent advances in human therapeutic cloning made by Hwang and colleagues have opened up new avenues of therapy for various human diseases. However, the major bottleneck of this new technology is the severe shortage of human donor oocytes. Egg-sharing in return for subsidized fertility treatment has been suggested as an ethically justifiable and practical solution to overcome the shortage of donor oocytes for therapeutic cloning. Because the utilization of shared oocytes in therapeutic cloning research does not result in any therapeutic benefit to a second party, this would necessitate a different management strategy compared to their use for the assisted conception of infertile women who are unable to produce any oocytes of their own. It is proposed that the pool of prospective egg-sharers in therapeutic cloning research be limited only to younger women (below 30 years of age) with indications for either male partner sub-fertility or tubal blockage. With regards to the proportion of the shared gametes being allocated to research, a threshold number of retrieved oocytes should be set that if not exceeded, would result in the patient being automatically removed from the egg-sharing scheme. Any excess supernumerary oocyte above this threshold number can be contributed to science, and allocation should be done in a randomized manner. Perhaps, a total of 10 retrieved oocytes from the patient may be considered a suitable threshold, since the chances of conception are unlikely to be impaired. With regards to the amount of subsidy being given to the patient, it is suggested that the proportion of financial subsidy should be equal to the proportion of the patient's oocytes being allocated to research. No doubt, the promise of future therapeutic benefit may be offered to the patient instead of financial subsidy. However, this is ethically controversial because therapeutic cloning has not yet been demonstrated to be a viable model of clinical therapy and any promises made to the patient might turn out to be illusionary. Hence, it is proposed that a tangible financial subsidy on the medical fees might be the better option for the patient's welfare.