Oocyte donation was carried out in 87 patients in 141 replacement cycl
es. These patients received oocytes from 108 women undergoing assisted
reproductive technology procedures at our centre. Standardized hormon
al replacement therapy and in-vitro fertilization procedures were perf
ormed. We divided recipients into four groups according to their age (
group A, 21-35 years; B, 36 - 40 years; C, 41-49 years; and D, 50-61 y
ears). Oocytes donors were 21-35 years old, and equally spread across
these different age groups. There were significant differences in the
pregnancy and implantation rates according to the age of the recipient
s; which were 45% and 23% respectively in women 21-35 years old (group
A) versus 23% and 10% in women 41-49 years old (group C). A compariso
n of data between oocyte donors and their specific recipients showed s
imilar results in donors and young recipients, with pregnancy rates of
45% and 42% and implantation rates of 23% and 19.5% respectively. Sta
tistically significant differences were found between donors and the o
lder recipients, pregnancy rates being 43% versus 23%, and implantatio
n rates 18% versus 10%. These data seem to demonstrate a lesser likeli
hood of pregnancy and implantation in older recipients because of incr
easing uterine age.