Could cleaved embryo morphology and morphokinetics be associated with prenatal and neonatal outcomes?

To evaluate if morphology and morphokinetics of cleaved embryos affect prenatal and perinatal outcomes.

This retrospective cohort study included 734 single fresh embryo transfer (SET) from ICSI from January 2014 to December 2020 at the Dijon University Hospital. Using time-lapse technology, embryos were defined as TOP or non-TOP according to morphological/morphokinetic criteria. Linear regression, adjusted for maternal factors, explored the association between cleaved-embryo quality and implantation rate, miscarriage rate, live birth rate, term, birthweight, and birthweight Z-score.

Multivariate analyses showed that non-implanted embryos were significantly more often out of the interquartile range than implanted embryos for cell events t2 (p = 0.019), t3 (p = 0.038), t4 (p = 0.013), ECC1 (p = 0.047), and ECC2 (p = 0.001). After implantation, the morphokinetics was significantly different for non-TOP embryos ending in miscarriage or live birth. A significant high risk of miscarriage was found for embryos with a short or long ECC1 (3.27 [95% CI: 1.44;8.37]. There was no significant difference in birthweight, birthweight Z-score, or term between TOP and non-TOP embryos. An association with increased birthweight was observed in multivariate analysis for pronuclei appearance (tPNa) (p = 0.001out of the range. Late tPNa was associated with a higher birthweight Z-score (p < 0.0001) while late pronuclei disappearance (tPNf) was associated with a lower Z-score (p = 0.006).

Morphological and morphokinetic parameters significantly influence implantation rates and the likelihood of a live birth from embryos with non-optimal morphological features. Birthweight Z-scores were significantly higher with late tPNa and lower with late tPNf.