Intracytoplasmic sperm injection improving embryo quality : Comparison of the sibling oocytes of non-male-factor couples

Our objective was to investigate whether the quality of embryos developed after intracytoplasmic sperm injection (ICSI) is better than that of conventional IVF embryos. Nine couples who previously achieved a normal rate of fertilization following IVF and four couples whose normal rate of fertilization was expected were involved in this study. The oocytes from those couples were randomly divided into two groups, group A by conventional insemination and group B by ICSI. The fertilization rate and quality of embryos were compared. Normal fertilization was achieved in 61% of the oocytes (83/136) after conventional insemination. In group B, 69% of the oocytes (99/144) achieved normal fertilization, although only 127 metaphase II oocytes were injected using the ICSI technique. More grade A embryos were obtained when the ICSI technique was used for fertilization than by conventional IVF (35.4 and 24.3%, respectively; P = 0.028). A similar fertilization rate can be achieved by ICSI in comparison with conventional IVF, when male factor is not involved. Embryos after ICSI have an improved quality.