Prediction of multiple pregnancies by the number of early cleaving embryos

Aim:  The aim of the present study was to investigate the number of early cleaving embryos as an effective predictor for multiple pregnancies in human in vitro fertilization (IVF). Methods:  The study analyzed early cleavage (EC) in 190 cycles of IVF. The EC of embryos to the two-cell stage was assessed at two time points, namely 25 and 27 h after insemination. Embryos that had cleaved at each time point were designated EC-1 and EC-2, respectively, whereas other embryos were designated as non-EC (NEC). The number of cycles with EC-1 embryos was not included in the results for the EC-2 group. Results:  Clinical pregnancy rates were significantly higher in the EC-1 group compared with the EC-2 and NEC groups (58.2%, 31.8% and 22.9%, respectively; P < 0.05). The pregnancy outcome was positively related to the number of EC-1 embryos. Multiple pregnancy rates were significantly increased up to 41.4% when the number of EC-1 embryos was two or more. Conclusions:  The results confirm that 25 h after insemination is a more effective critical time point for the selection of EC embryos and that the number of EC embryos could be a useful parameter for the prediction of multiple pregnancies.