Can We Rely on Only Morphokinetic Parameters to Detect Embryo Aneuploidy?

To re-investigate the morphokinetic characteristics of aneuploidy in embryos from randomly selected IVF-PGS (preimplantation genetic screening) patients whose ages are normally distributed. Retrospective cohort study. Data used were from our routine IVF-PGS patients (n=18) whose ages are normally distributed [25.8-43.6]. Autologous fresh oocytes (n=185) from these patients were incubated in Time-Lapse microscope (EmbryoScope: Unisense Fertilitech, Denmark) following insemination. After Day 3 biopsy (n=152), ploidy was analyzed using array-comparative genome hybridization (aCGH). According to PGS results, these embryos classified into two groups, euploid (n=46) and aneuploid (n=106). The morphokinetic parameters tested in this study, including three new parameters* [oocyte diameter, distance of pronuclei (PNs) and ratio of PN diameters] are listed in Table 1. Data were analyzed using one way ANOVA and χ2-test, and Pearson correlation test. In this study, aeuploidy is only correlated with patient’s age (r=.331, p< .0001). Within the two groups of embryos, the mean differences for the tested morphokinetic parameters are tabulated below.Tabled 1The Mean Differences of Morphokinetic Parameters within GroupsParametersEuploidyAneuploidyP-valueAge34.1 ±4.237.5 ±4.60.000**Oocyte diameter*159.3 ±11.0159.6 ±7.40.835Distance of PNs*44.2 ±5.049.7 ±49.50.462Ratio of PN diameters*1.1 ±0.21.0 ±0.20.386Granular cytoplasm10.9%11.3%0.935tPB2 (time of polar body extrusion)4.7 ±3.34.8 ±3.40.810tPNa (time of PN appearance)10.5 ±3.510.8 ±3.90.627tPNf (time of PN faded)24.2 ±4.624.6 ±6.50.686cc2 (time of 2nd cell cycle; t3-t2)7.5 ±5.87.8 ±6.50.673s2 (time of synchrony of 2nd cell cycle; t4-t3)4.5 ±5.25.4 ±5.50.308cc3 (time of 3rd cell cycle; t5-t3)15.0 ±7.114.9 ±6.70.954tM (time from insemination to formation of a morula)89.6 ±12.389.6 ±12.40.984tSB (time from insemination to start of blastulation)100.6 ±11.699.9 ±8.90.750tB (time from insemination to formation of a full blastocyst)106.7 ±8.9106.9 ±8.00.925PN score grade I+II80%88.6%0.332Irregular Division10.9%21.7%0.114Recleavage8.7%6.6%0.647Multinucleation at 2 cell stage32.6%36.8%0.621Blastomere size (even)37.0%33.0%0.268 Open table in a new tab The results here revealed that aneuploidy cannot be predicted using the morphokinetic parameters tested by time-lapse microscopy without PGS screening [1]. Patient’s age in the PGS cases should also be considered as a parameter for further time-lapse studies.