There is a risk of multiple pregnancies if 3 embryos are transferred into uterus. Statistically, in a survey of 885 women who were undergone IVF, there were 404 pregnancies, i.e., 46% (404/885) chance of pregnancy by replacing 3 embryos. Excluding miscarriages, 289 women gave birth, i.e., 33% (289/885) chance of successfully giving birth by replacing 3 embryos. Among these 289 women who successfully gave birth, 92 women delivered twins, i.e. 10% (92/885) twins by transferring 3 embryos. 25 women delivered triplets, i.e., 3% (25/885) by transferring 3 embryos.

In order to minimize the risk of multiple pregnancies, except in cases where the chances of pregnancy may be reduced, e.g., older patient, un-satisfactory quality of embryo, or history of previous 3 IVF treatment failures, there is no advantage in terms of pregnant success in replacing more than two embryos. Since at normal and favorable circumstances, to transfer two embryos does not reduce the chances of pregnancy, whereas it may reduce the occurrence of triple or twin pregnancies by almost one third.