Embryos with some chromosomal abnormalities can lead to healthy babies following in vitro fertilisation, a European conference has heard.
Italian researchers have reported success with so-called mosaic embryos, which have two or more genetically distinct cell lineages, usually one with a chromosome abnormality and the other with normal chromosomes.
Dr Francesco Fiorentino and colleagues at the European Hospital IVF Centre in Rome, Italy, carried out tests involving 73 women and concluded that the results "confirm that mosaic embryos can develop into healthy euploid newborns".
Their findings were presented yesterday (4 July) at the 33rd Annual Meeting of the European Society of Human Reproduction and Embryology. They point out that the success or failure following the transfer of a mosaic embryo depends on the extent of the mosaicism and chromosomal abnormality in the embryo.
Transfer of mosaic embryos with above 50% chromosomally abnormal cells led to a live birth rate of 16.7% and a miscarriage rate of 10%. For those with below 50% chromosomally abnormal cells there was a live birth rate of 39.5% and a miscarriage rate of 7.0%.
"Priority for transfer should be given to mosaic embryos with low levels of aneuploidy," says Dr Fiorentino, as these are more likely to self-correct and develop into a healthy new-born.
* Another study reported to the conference found that automated embryo assessment is more accurate than assessment by embryologists.
Usually, embryo quality is determined with a visual assessment of an embryo’s shape and development.
But this is less effective than an automated assessment approach, which includes detecting chromosomal abnormalities, say Dr Professor Jose Celso Rocha and his team at Sao Paulo State University, Brazil.
Fiorentino, F. et al. The extent of chromosomal mosaicism influences the clinical outcome of in vitro fertilization treatments. Abstract O-182, presented on 4 July 2017 at the 33rd Annual Meeting of the European Society of Human Reproduction and Embryology.
Celso Rocha, J. et al. Using artificial intelligence to improve blastocyst morphology evaluation. Abstract O-162, presented 4 July 2017 at the 33rd Annual Meeting of the European Society of Human Reproduction and Embryology.
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