EDITORIAL COMMENT

In some infertile men, who have nonobstructive azoospermia, round spermatids (haploid male germ cells that have completed meiosis) are the most mature cells that are found after testicular sperm extraction operation. The microinjection of a round spermatid into an oocyte is called round spermatid injection (ROSI). Currently, human ROSI is considered a very inefficient procedure and of no clinical application. In this study, the authors reported the birth and development of 14 children born to twelve women following ROSI of 734 oocytes activated by an electric current. They concluded that the success was the ability to identify round spermatids accurately and oocyte activation by electric stimulation. All children were born after ROSI without any unusual physical, mental, or epigenetic problems. In this recent study, it has unexpectedly been shown that round cells, which are immature spermatozoa, may have ability to achieve pregnancy and live birth in human. ROSI may be considered an option and last chance for men whose germ cells are unable to develop beyond the round spermatid stage to have their own genetic offspring.