Quality of Blastocysts Created by Embryo Splitting: A Time-Lapse Monitoring and Chromosomal Aneuploidy Study

The aim of this study was to screen the potential of human embryos to develop into expanding blastocysts following in vitro embryo splitting and then assess the quality of the generated blastocysts based on chromosomal characteristics and using morphokinetics.

In this experimental study, a total of 82 good quality cleavage-stage donated embryos (8- 14 cells) were used (24 embryos were cultured to the blastocyst stage as controls and 58 embryos underwent in vitro splitting). After in vitro splitting, the blastomere donor and blastomere recipient embryos were named twin A and twin B, respectively. Morphokinetics and morphological parameters were evaluated using a time-lapse system in the blastocysts developed from twin embryos. Aneuploidy of chromosomes 13, 15, 16, 18, 21, 22, X and Y were analyzed in the twin blastocysts.

Following in vitro splitting, of the 116 resulting twin embryos, 80 (69%) developed to the expanded blastocyst (EBL) stage compared to 21 (87.5%) embryos in the control group (P>0.05). The morphokinetics analysis suggested that the developmental time-points were influenced by the in vitro splitting. Moreover, the blastocysts developed from A and B twins had impaired morphology compared to controls. Regarding chromosome abnormalities, there was no significant difference in the rate of aneuploidy or mosaicism between the different groups.

This study showed that while no chromosomal abnormalities were seen, in vitro embryo splitting may affect the embryo morphokinetics.