Subject Ninety infertile women, aged 23-39 years, with an infertile duration of 3-8 years, were enrolled from our infertility treatment clinic between January and June 2008. The selection criteria for participants were only those women who were first going to undergo IVF or ICSI treatment. Women who were treated with natural cycle IVF or had no appropriate embryo for ET were excluded. The infertility factors were identified as the following: tubal (n=54), unexplained (n=3), male n=22), endometriosis (n=9), others (n=2). The selection and enrollment for each subject was decided by three same physicians. All subjects were informed that this procedure was a new technique, and that its effectiveness has not been confirmed, although an optimal outcome in patients with blastocyst transfer was obtained by using this technique for the same purpose (6). During the selection procedure, four eligible subjects opted not to participate when counseled about the uncertain of effectiveness, and other two subjects declined to randomize. Finally, 90 eligible patients were enrolled.