Efficacy of oocytes donated by older women in an oocyte donation programme

Population and insemination studies indicate that women experiencedeclining fertility with ageing. The question therefore ariseswhether older women are suitable oocyte donors. This study addressesthis issue by examining the relationship between oocyte donorage and clinical outcome in a large oocyte donation programme.We retrospectively reviewed data from 458 consecutive oocytedonation cycles completed by 164 different designated oocytedonors. Data were divided into two groups: group A, cycles withdonors aged 21–30 years at the time of follicular aspiration(193 cycles, 88 donors); and group B, cycles with donors aged31–40 years at the time of follicular aspiration (265cycles, 86 donors). Five donors, because of ageing during repetitivedonations, contributed data to groups A and B. In a given cycle,all oocytes for a recipient came from only one designated donor.Comparing the two donor groups, there was no difference in theamount of gonadotrophin used to achieve optimal stimulation;however, more oocytes were obtained from group A than groupB donors (16.8 ± 6.9 and 15.1 ± 8.1 respectively,P < 0.05). Similar percentages of oocytes were fertilizedin each group, resulting in the transfer of comparable numbersof embryos (4.5 ± 1.1 and 4.4 ± 13 respectively).Comparable clinical pregnancy rates were achieved (group A,36%; group B, 37%). The spontaneous abortion rates were alsosimilar (group A, 20%; group B, 12%), resulting in comparableongoing and delivered pregnancy rates per cycle (group A, 29%;group B, 32%) and per embryo transferred (group A, 6.4%; groupB, 7.3%). In conclusion, women of proven fertility should notbe excluded from donating oocytes simply because of their age.There exists a cohort of fertile women who resist the decreasingfecundity and increasing spontaneous abortion rates associatedwith ageing. With careful screening, many women of proven fertilitycan donate oocytes until the age of 40 years with an efficacyequal to that of younger women. Given the relative shortageof suitable oocyte donors, and increasing requests from recipientswith previous donor oocyte babies to obtain oocytes from thesame, now older, donor, the findings of this study are of practicalclinical importance.