Comparative study of implantation rate in cleavage embryo transfer vs blastocyst transfer among couples undergoing in vitro fertilization for treatment of infertility (original) (raw)

In vitro fertilization has conventionally involved transfer of 4-8 cell embryo (also called cleavage embryos) into the uterus. This was considered necessary because culture media and lab systems could not support further growth of embryo. However, new and advanced culture media and laboratory techniques now permit in vitro growth up to blastocyst stage. This has generated a healthy debate regarding optimum stage of transfer of embryos into the uterus post-IVF. Objectives: To study and compare implantation rates of cleavage embryos with blastocyst embryos and determine which would give better pregnancy outcome. Materials and methods: One hundred couples reporting for IVF were divided randomly into two groups. Group A comprised fifty couples in whom cleavage embryos were transferred. Group B comprised 50 couples in whom blastocysts were transferred. In both groups couples were in 20-35 year age group. In both groups maximum two embryos were transferred into the uterus. Results and conclusion: The implantation rates in both groups were similar. The abortion rates were also similar. However, in cases where only one embryo was transferred, the implantation rate with balstocyst embryo was double that of the 4-8 cell stage embryo. Thus blastocyst transfer has the potential benefit of reducing incidence of multiple pregnancies frequently seen in IVF pregnancies.