Variables which influence the selection of an egg donor.

We have analysed the different variables which affected the efficacy of egg donation in our assisted reproductive technology unit. Potential donors (n = 108) were divided into two groups. Group 1 comprised partial donor (PD) subjects who underwent assisted reproduction for the treatment of their infertility and who agreed altruistically to donate extra eggs not used during their own cycles (n = 31). Group 2 consisted of full donor (FD) subjects who donated all the eggs recovered during their ovarian stimulation cycle (n = 77) and included sister to sister donation, volunteers and patients undergoing diagnostic or sterilization laparoscopies. The entire donor population was divided into two sub-populations by age, those under 30 and 31-39 years old, and correlated with the pregnancy rate in their recipients. From this analysis, a higher pregnancy rate was observed when the oocytes were provided by the younger group of donors (54 versus 36%). We did not find a significant difference in the recipients' pregnancy rate, according to the previous reproductive performance of their donors. Even though FD and PD yield similar pregnancy rates during the fresh cycles, the availability of cryopreserved embryos in the former group enhances the cumulative pregnancy rate.