Abstract
PURPOSE: Intracytoplasmic sperm injection (ICSI) of some sibling oocytes may have a beneficial effect in couples going through in vitro fertilization for causes of infertility not related to the male factor. Our purpose was to critically appraise the randomized controlled studies done in this area and arrive at some recommendations. METHODS: The four controlled trials done so far have utilized similar methodology, i.e., they randomly allotted sibling oocytes to ICSI versus standard insemination in patients going through in vitro fertilization and embryo transfer. RESULTS: In the first trial reported in 1995 there was no difference in fertilization rate, whereas the later trials reported in 1997, 1999, and 2000 showed improvement with ICSI that reached statistically significant level in the last two studies. CONCLUSIONS: Total fertilization failure of an in vitro fertilization cycle can be prevented and fertilization can be improved if half of sibling oocytes are subjected to ICSI.