In their research Alison Campbell and colleagues of CARE Fertility, Nottingham, went one step further, describing the use of morphokinetic analysis to identify those embryos that have an abnormal chromosomal constitution. In that study, they cultured embryos under time lapse imaging to day 5, by which time they formed blastocysts. These were then biopsied by removing a few of the cells from the outer layer of the embryo, which will normally contribute only to the placenta. The biopsy was then analyzed for its chromosomal constitution. The authors then related the chromosomal make up of each embryo to its morphokinetic history. They found that a proportion of embryos with chromosomal abnormalities were delayed in initiating blastocyst formation and also reached the full blastocyst stage later than did normal embryos. The authors conclude that using this approach they could avoid exposing at least a subset of the embryos to invasive biopsy procedures.
"This non-invasive model for the classification of chromosomal abnormality may be used to avoid selecting embryos with high risk of aneuploidy while selecting those with reduced risk," said lead author Alison Campbell.
The same group has now applied this risk classification model retrospectively to examine the pregnancy outcomes in a series of unselected IVF patients without the use of PGS. A significant improvement in both implantation and live birth rates was observed when low risk embryos were transferred.
Scientist Markus Montag of the Department of Gynecological Endocrinology and Fertility Disorders, University Clinics of Heidelberg, said: "The idea of using time-lapse imaging and morphokinetic analysis is intriguing, because having available a completely non-invasive procedure to pred
|Contact: Greyling Peoples|