Prediction of live birth - selection of embryos using morphokinetic parameters.

BACKROUND: The goal of assisted reproduction is for a couple treated with IVF techniques to end the treatment by giving birth to a healthy baby. A neccessary presumption for success is the identification of the best embryo with high implantation and developmental potential. One option is to select an euploid embryo by invasive preimplantaion genetic testing for aneuploidy (PGT-A) or it is possible to select the best embryo by non-invasive time-lapse monitoring (TLM), specifically based on morphokinetic parameters and morphological markers that are able to identify an embryo with high developmental potential. MATERIALS AND METHODS: The study involved a total of 1060 embryos (585 euploid and 475 aneuploid embryos after PGT-A) with good morphology from 329 patients in the period 01/2016-10/2021. All embryos were cultured in a time-lapse incubator, trophectoderm (TE) cells biopsies for PGT-A examination were performed on day 5 (D5) or day 6 (D6) of culture. During the study period, 225 frozen embryo transfers (FET) of one euploid embryo were performed. Based on the treatment outcome, the embryos were divided into 2 groups - euploid embryos, which led to the birth of a healthy child, and euploid embryos that did not show fetal heartbeat (FHB) after FET. RESULTS: Based on the statistical analysis of the embryos without implantation and the embryos with live birth, it is clear that the morphokinetic parameters t5 (time of division into 5 cells) and tSB (time of start of blastulation) are significantly different. CONCLUSION: The results suggest that of the morphokinetic parameters tSB and t5 are predictive indicators for selecting an embryo with high developmental potential and with a high probability of achieving the birth of a healthy child.

Differences in Morphokinetic Parameters and Incidence of Multinucleations in Human Embryos of Genetically Normal, Abnormal and Euploid Embryos Leading to Clinical Pregnancy.

The selection of the best embryo for embryo transfer (ET) is one of the most important steps in IVF (in vitro fertilisation) treatment. Preimplantation genetic testing (PGT) is an invasive method that can greatly facilitate the decision about the best embryo. An alternative way to select the embryo with the greatest implantation potential is by cultivation in a time-lapse system, which can offer several predictive factors. Non-invasive time-lapse monitoring can be used to select quality embryos with high implantation potential under stable culture conditions. The embryo for ET can then be selected based on the determined morphokinetic parameters and morphological features, which according to our results predict a higher implantation potential. This study included a total of 1027 morphologically high-quality embryos (552 normal and 475 abnormal PGT-tested embryos) from 296 patients (01/2016-06/2021). All embryos were cultivated in a time-lapse incubator and PGT biopsy of trophectoderm cells on D5 or D6 was performed. Significant differences were found in the morphological parameters cc2, t5 and tSB and the occurrence of multinucleations in the stage of two-cell and four-cell embryos between the group of genetically normal embryos and abnormal embryos. At the same time, significant differences in the morphological parameters cc2, t5 and tSB and the occurrence of multinucleations in the two-cell and four-cell embryo stage were found between the group of genetically normal embryos that led to clinical pregnancy after ET and the group of abnormal embryos. From the morphokinetic data found in the PGT-A group of normal embryos leading to clinical pregnancy, time intervals were determined based on statistical analysis, which should predict embryos with high implantation potential. Out of a total of 218 euploid embryos, which were transferred into the uterus after thawing (single frozen embryo transfer), clinical pregnancy was confirmed in 119 embryos (54.6%). Our results show that according to the morphokinetic parameters (cc2, t5, tSB) and the occurrence of multinucleations during the first two cell divisions, the best euploid embryo for ET can be selected with high probability.

Non-Invasive Human Embryo Metabolic Assessment as a Developmental Criterion.

The selection of a highly-viable single embryo in assisted reproductive technology requires an acceptable predictive method in order to reduce the multiple pregnancy rate and increase the success rate. In this study, the metabolomic profiling of growing and impaired embryos was assessed on the fifth day of fertilization using capillary electrophoresis in order to find a relationship between the profiling and embryo development, and then to provide a mechanistic insight into the appearance/depletion of the metabolites. This unique qualitative technique exhibited the appearance of most non-essential amino acids and lactate, and depleting the serine, alanyl-glutamine and pyruvate in such a manner that the embryos impaired in their development secreted a considerably higher level of lactate and consumed a significantly higher amount of alanyl-glutamine. The different significant ratios of metabolomic depletion/appearance between the embryos confirm their potential for the improvement of the prospective selection of the developed single embryos, and also suggest the fact that pyruvate and alanyl-glutamine are the most critical ATP suppliers on the fifth day of blastocyst development.