The use of morphokinetic parameters to select all embryos with full capacity to implant.

Purpose: Embryo kinetics analysis is an emerging tool for selecting embryo(s) for transfer. The aim of the present study was to determine morphokinetic parameters easily usable in the laboratory and predictive of embryo development and, most importantly, of embryo competence in producing a clinical pregnancy after day 5 transfer.

Methods: A retrospective time-lapse monitoring analysis of morphokinetic parameters for 72 fully implanted embryos (group A) were compared to 106 non-implanted embryos (group B), and to 66 embryos with arrested development from the same pool of group A. All the embryos were from 78 patients undergoing ICSI treatment and day 5 embryo transfers.

Results: A day 3 embryo will develop into a viable blastocyst if the following ranges of morphokinetic parameters are met: t1 (between 18.4 h and 30.9 h post-ICSI), t2 (21.4-34.8 h), t4 (33.1-57.2 h), t7 (46.1-82.5 h), t8 (46.4-97.8 h), tC-tF (7.7-22.9 h) and s3 (0.7-30.8 h). On day 5 embryos with the highest probability to implant are those with a cc3 between 9.7 h and 21 h.

Conclusions: Morphokinetic parameters are helpful to make appropriate decisions for the disposition of each embryo. It is recommended that each laboratory should determine its own ranges of in vitro development (IVD-MKP) and implantation-associated (IMP-MKP) morphokinetic parameters.