Use of both early cleavage and day 2 mononucleation to predict embryos with high implantation potential in intracytoplasmic sperm injection cycles

Objective: To evaluate the value of early cleavage and day 2 mononucleation as combined parameters in predicting the implantation potential of embryos. Design: Prospectively designed retrospective cohort analysis. Setting: Private IVF center. Patient(s): Two hundred eighty-seven ICSI cycles were evaluated in four groups according to the presence of early cleavage and monoucleation in all (ECM), some (pECM, ECpM), or none (noECnoM) of the transfer embryos. Intervention(s): None. Main Outcome Measure(s): Embryo quality and pregancy and implantation rates. Result(s): The cycle characteristics, embryo quality, and pregnancy rates were similar when all (ECM) or some (pECM and ECpM) transfer embryos displayed these parameters. The poorest cycle characteristics and outcome were observed in the absence of both parameters (noECnoM). When early cleavage was present, a higher implantation rate was observed when all transfer embryos displayed mononucleation at day 2 (ECM) than when this was the case only in some (ECpM). Conclusion(s): Combination of early cleavage and day 2 mononucleation improves selection of embryos with high implantation potential in ICSI cycles with good prognosis.