Y. Yaron et al., THE OPTIMAL NUMBER OF EMBRYOS TO BE TRANSFERRED IN SHARED OOCYTE DONATION - WALKING THE THIN LINE BETWEEN LOW PREGNANCY RATES AND MULTIPLE PREGNANCIES, Human reproduction, 12(4), 1997, pp. 699-702
There has been growing concern about the number of multiple gestations
resulting from assisted reproductive technologies. For in-vitro ferti
lization (IVF), there are guidelines concerning the number of embryos
to be transferred, In oocyte donation, however, there is a paucity of
studies addressing this issue and common practice is extrapolated from
standard IVF procedures, This may not be correct since endometrial re
ceptivity has been shown to be altered in oocyte donation, Thus the pu
rpose of this study was to assess the optimal number of embryos to be
transferred in oocyte donation, The study population included 254 pati
ents with ovarian failure who underwent a total of 601 embryo transfer
s in a single shared oocyte donation programme, Pregnancy rates (PRs),
multiple pregnancies, triplet pregnancy rates, and implantation rates
were evaluated according to the number of embryos transferred. A sign
ificant linear increase in PRs was noted with the increasing number of
embryos transferred up to five (11.1% for one embryo, 36.7% for five
embryos), Multiple pregnancies increased significantly from 15.8% for
two embryos transferred, to 44.4% for five embryos, The rate of triple
t pregnancies also increased from 2.7% for three embryos transferred,
to 8.3% for five embryos, Optimization of the number of embryos to be
transferred is discussed.