Evaluation of fragmented embryos implantation potential using time‐lapse technology

Abstract

Aim To examine the implantation potential of fragmented embryos that underwent morphokinetic evaluation in a time‐lapse incubator. Methods A retrospective study analyzing 4210 Day 5 embryos which were incubated in a time‐lapse incubator, between 2013 and 2019. Embryos with more than 5% fragmentation (379 embryos) were included in the study. Embryos selected using the general model and re‐examined by our in‐house model. Embryo fragmentation percentage was documented from the first cell‐division (start fragmentation) to its maximal percentage (final fragmentation), and the ratio between them (fragmentation worsening). Data were analyzed with relation to embryo development, embryos transfer or freezing, clinical pregnancy, and live birth rates. Results Embryo fragmentation and morphokinetics were found to be independent variables for clinical pregnancy achievements. A higher fragmentation worsening was noted among discarded embryos compared to transferred or frozen embryos (p < 0.0001). Advanced maternal age had a significant negative effect on fragmentation (p < 0.001). Missed abortion rates were similar in fragmented embryos that implanted compared with the overall population. Live birth rates were comparable among embryos which were selected for transfer or freezing by their morphokinetics and had different severity of fragmentation. Conclusion Our study shows that fragmented embryos have a potential to implant and therefore should be selected for transfer. Laboratories which do not use time‐lapse incubators for embryo selection, should consider transferring fragmented embryos, since they have an acceptable chance for live birth. Calculation of fragmentation worsening may enhance our ability to predict embryo development. Further research with analysis of more fragmented embryo maybe beneficial. This study was approved by the local ethics committee No. 0010‐19 CMC on April 18th, 2019.

Effect of cytoplasmic fragmentation on embryo development, quality, and pregnancy outcome: a systematic review of the literature

“…A total of six studies in this review focused on this relationship (Table 4 ). Three of the studies found a positive correlation between patient age and degree of embryo fragmentation [ 67 – 69 ]. The other three studies found no age-related correlation between embryo fragmentation or quality [ 7 , 70 , 71 ].…”

“…Fragmentation rate was higher in patients ˃35 compared to patients ≤35 years old. It seems that the lower quality of oocytes in older patients results in increasing fragmentation [ 69 ]. Overall, the included studies have differing conclusions on the effect of maternal age and CF; varying definitions and analysis of CF remain a limitation.…”

“…In contrast, Lahav-Baratz recently showed that there was no association between fragmentation rate and abortion or live birth rate. It was concluded that fragmented embryos still have implantation potential and could be considered for transfer when applicable [ 69 ].…”