Polycystic ovarian syndrome (PCOS) patients are at higher risk of ovarian hyper stimulation syndrome (OHSS) due to the high dose of gonadotropin in IVF. To avoid the possibility of OHSS, IVM techniques have been developed and employed in clinical settings. However, IVM delivers lower pregnancy rates and birth rates than IVF. The objective of this study was to assess whether IVM treatment affects embryo development events together with morphokinetic parameters compared with IVF, and to identify the morphokinetic parameters specific to embryos that were suitable for implantation in IVM cycles. Retrospective study. The subjects were 41 couples who underwent 50 cycles of IVM at our clinic, from May, 2013 to Nov., 2015. After the failure of IVM treatment, 12 couples underwent standard IVF treatment. We assessed 194 embryos derived from IVM-ICSI and 48 embryos derived from IVF-ICSI. Their treatment outcomes were analyzed with morphokinetic events (cell division and interval of cell cleavage) by Primovision (vitrolife Sweden), and rate of clinical outcome. Moreover in IVM cycles, these time points were also compared between transferred embryos that implanted or did not implant. IVM zygotes showed significantly lower good quality embryo on day3, blastocyst formation, and good blastocyst rates compared with IVF. There were no differences in time points of cell division (tPNa to t8), pregnancy and abortion rates between the two groups. However, there were significant differences in synchrony of the second cell cycles (t4-t3:S2) (S2:4.5±5.0h vs. 1.4±2.3h, P=0.0002), and the rate of direct cleavage of one to three, or there to five cells was significantly higher in the IVM group (90/194 46.4% vs. 9/48 18.8%, P=0.0016). In the IVM group, there were no differences in development time points between implanted and non-implanted embryos. IVM zygotes showed increased abnormal cleavage compared with IVF; however, there were no significant differences in pregnancy rate or abortion rate between IVM and IVF. We rejected these abnormal cleaved embryos for transfer, indicating that in order to improve the pregnancy rate it is important to exclude the abnormal cleaved embryo, such as direct cleavage, from embryo transfer in IVM treatment.