One year's experience with elective transfer of two good quality embryos in the human in-vitro fertilization and intracytoplasmic sperm injection programmes

High incidences of multiple pregnancies, after transferring a maximum of three embryos, were observed after in-vitro fertilization (IVF) treatment. In a randomized study, it was demonstrated that, after taking into account embryo quality and other positively interfering parameters, an elective transfer of two good quality embryos does not significantly influence the pregnancy rate. The intracytoplasmic sperm injection (ICSI) technique was successfully developed in the meantime and high incidences of multiple pregnancies were also obtained after ICSI. The question arose whether after ICSI there was also room for elective double embryo transfer in a well-defined patient group. This report covers 1 year of IVF and ICSI treatment and the results are presented in relation to the number of embryos transferred. The embryo development is similar for zygotes obtained after IVF and ICSI; for both techniques 63% of the zygotes develop to type A-B embryos and 13% to type C embryos. There is also no difference in the pregnancy rate after ICSI or IVF. Globally, after IVF, 307 out of the 766 double and triple transfers (40.1%) and 317 out of 774 double and triple transfers (40.9%) after ICSI resulted in a positive HCG. After IVF, 73.9% (227) and after ICSI 76.3% (242) of the pregnancies were evolutive. Neither was there any difference between the two techniques as regards the implantation rate per transferred embryo. After IVF, 22.8% of the transferred embryos implanted compared with 21.8% after ICSI. When the elective double embryo transfers were compared, no difference was found between IVF and ICSI. After IVF, 102 of the 211 elective double transfers (48.1%) resulted in a pregnancy versus 93 out of 225 (41.3%) after ICSI [not significant (NS)]. A high implantation rate per transferred embryo (IVF: 33.2%; ICSI: 26.9%, NS) was obtained in this elective double transfer category, as was also reported in the randomized study. These data confirm the results obtained in our randomized study and the effectiveness of the elective double embryo transfer for IVF as well as for ICSI.