Does Female Age Affect Embryo Morphokinetics?

Introduction – Age-related changes affects oocyte quality and the subsequent women reproductive capacity. The study of embryo morphokinetics through time-lapse microscopy has been employed for the purpose of embryo scoring, to select embryos for transfer. Studying embryonic morphokinetic of elder women may provide new clues to their decline in fertility.

Aim – To compare the morphokinetic parameters of preimplantation development between embryos of aged versus young women

Methods – The dataset of 1148 embryos included 495 embryos from women ≥ age 42 years who underwent IVF between Aug. 2012 and Dec. 2014, in our unit and cultured in the EmbryoScope^TM, and 653 control embryos of women < age 38 who underwent IVF during that same period. Time-points of key embryonic events were annotated and analyzed with the EmbryoViewer combined with statistics.

Results – The duration of the third cell cycle (cc3) was significantly longer in embryos of older women (14 h vs. 13.5 respectively; p<0.05). No significant differences were observed in the timing of any other key embryonic events, cell cycle times or cleavage synchronicity between the study and the control groups (tPNf, t2-t8, cc2, s2, s3; p>0.05). Interestingly, a significantly higher percentage of embryos of older women arrested at 4-7 cells resulting in less embryos reaching the 8 cell (66% vs. 72% respectively; p<0.05).

Conclusions – Morphokinetic analysis of preimplantation embryos enabled us to demonstrate that the third cell cycle in embryos of older woman is prolonged compared to those of younger women, possibly affecting embryonic arrest in spite of normal cleavage.