Early cleavage predicts the viability of human embryos in elective single embryo transfer procedures.

BACKGROUND The reduction of multiple pregnancies by using elective single embryo transfers (eSET) requires critical and careful selection of the embryo for transfer. The current study was undertaken to assess whether early cleavage could be used as a marker of embryo competence in eSET procedures. METHODS The study included analysis of 178 eSET procedures. All embryos were checked for early cleavage at 25-27 h post insemination or ICSI. The embryos that possessed two cells at 25-27 h post insemination or ICSI were designated as 'early cleavage' (EC) embryos and those that had not yet cleaved were classified as 'no early cleavage' (NEC) embryos. Selection of the embryo for transfer was based on embryo morphology and growth rate on day 2 and not early cleavage. Clinical parameters were compared between 72 EC and 106 NEC single embryo transfers. RESULTS A significantly higher clinical pregnancy rate was observed after transfer of EC (50%) than NEC (26.4%) embryos. CONCLUSIONS The current study provides compelling evidence that EC embryos possess significantly higher developmental competence than NEC embryos.