Oocyte donation: a review.

Oocyte donation provides an option for achieving pregnancy in women lacking functioning gonads, or in whom IVF techniques have failed to harvest adequate oocytes, or those who do not wish to use their own gametes because of hereditary disease. In agonadal women, artificial menstrual cycles are required before proceeding to gamete donation. A fixed cyclical steroid replacement schedule of oestradiol (E2) valerate and progesterone (P4) pessaries was initially used, but the need for synchrony between donor and recipient cycles, and the narrow window for implantation limited the transfer of fresh embryos. Donor-recipient cycle asynchrony can be overcome by using frozen-thawed embryos, or by extending the follicular phase in the recipient to widen the transfer window. Twenty-two pregnancies have now been achieved by the Monash/Epworth group, resulting in the birth of 13 healthy infants. There were no statistically significant differences in pregnancy rates (per transfer) between transfers in natural cycles (14%, four pregnancies) and steroid replacement cycles (24%, 16 pregnancies). Five pregnancies (36%) were established in women treated with 2 mg of E2 daily 13-18 days before embryo transfer with P4 starting on the day of or the day following oocyte retrieval. E2 was continued for a median of 85 days (range 49-110) and P4 for a median of 86 days (range 49-133) after the supposed last menstrual period. All but one delivery was by caesarean section. There were no perinatal deaths and no ectopic pregnancies.