Abstract: In vitro embryo splitting or twinning is a method of reproductive cloning that involves dividing a single early-stage embryo into two or more individual cells and growing them as identical embryos. The first successful intentional in vitro human embryo splitting, reported in 1993, sparked a heated ethical discussion on the cloning of human embryos. Later, the intricacies of the ethical debate related to cloning through human embryo splitting were globally recognized. In response to this, several countries and international organizations have implemented prohibitions either through legal statutes, official decrees, or public statements. However, most of the studies reported the post-implantation spontaneous embryo splitting in utero that results into monozygotic twins or multiples and aren’t fall under the prohibitions of cloning. Recently, rare cases of unintentional in vitro embryo splitting were confirmed during their culture mostly due to naturally zona-free oocytes or zona manipulations. Due to the ambiguity of current legislation to discriminate between intentional or unintentional in vitro embryo splitting, the fate of those embryos to transfer or not, remains a question. After assessing the potential risk associated with, there is a need to reconsider the prohibitions imposed on transfer of unintentionally generated split embryos in poor responders and advanced maternal age patients undergoing IVF treatment, where the use of donor gametes is also prohibited. This review paper describes the various IVF laboratory procedures that rarely and unintentionally generates split embryos. Moreover, the cellular and molecular changes occurring in split embryos and ethical considerations about use of split embryos to transfer are also deliberated.
Indexed in Index Copernicus
