Evaluation of human embryo development in fertilization- and intracytoplasmic sperm injection-fertilized oocytes: A time-lapse study.

OBJECTIVE

We investigated whether the insemination method ( fertilization [IVF] or intracytoplasmic sperm injection [ICSI]) affected morphokinetic events and abnormal cleavage events in embryonic development.

METHODS

A total of 1,830 normal fertilized embryos were obtained from 272 IVF and ICSI cycles that underwent ovum retrieval culture using a time-lapse system (Embryoscope) from June 2013 to March 2015. All embryos were investigated by a detailed time-lapse analysis that measured the developmental events in the hours after IVF or ICSI insemination.

RESULTS

No significant differences were observed between the two groups regarding clinical outcomes (>0.05). ICSI-derived embryos showed significantly faster morphokinetics than those derived from conventional IVF, from the time to pronuclear fading to the time to 6 cells (<0.05). However, no significant differences were found from the time to 7 cells to the time to expanded blastocyst (>0.05). There were no differences in abnormal cleavage events between the two groups (>0.05); they showed the same rates of direct cleavage from 1 to 3 cells, 2 multinucleated cells, 2 uneven cells, and reverse cleavage.

CONCLUSION

The morphokinetics of embryo development was found to vary between IVF- and ICSI-fertilized oocytes, at least until the 6-cell stage. However, these differences did not affect the clinical outcomes of the embryo. Additionally, no significant differences in abnormal cleavage events were found according to the fertilization method.