16 August 2010
ByAppeared in BioNews 571
The successful use of PGS (preimplantation genetic screening) can be linked to access to appropriate technologies and the skill level and techniques used by embryologists, new research has found.
Dr Santiago Munne, founder of Reprogenetics and leading expert in the field, and his team reviewed and evaluated the current use of PGS. In their report, published in July's Fertility and Sterility journal, they show 'that clinics using optimal methodology, highly skilled technicians and the most advanced chromosomal assessment techniques have consistently shown an improvement in assisted reproductive technology (ART) results with PGD'.
The review identifies a 'blueprint' for successful PGS. This consists of appropriate patient selection by considering maternal age and number of available embryos, using highly and appropriately trained scientists, taking a single cell biopsy from the embryo, studying at least eight significant chromosomes and carrying out all work out in a PGS laboratory with an error rate lower than 10 per cent.
The need to review current technologies stems from currently inconsistent conclusions from previous trials, creating a debate surrounding the use of PGS to improve IVF pregnancy results. The report noted that broadly varying biopsy and chromosome analysis were used, thus producing contradictory results. Dr Munne's team also reported that despite many studies indicating significant advantages of PGS, the notion of its full benefits was not yet uniformly shared, with results varying widely amongst laboratories performing PGS.
PGS is commonly used to study the extracted chromosomes used in ART and is often vital in successful embryo selection. During this process, embryos created through IVF are examined for genetic defects before implantation in the female's uterus. This allows for only healthy embryos to be selected, potentially increasing implantation success rate, reducing spontaneous abortion and the likelihood of the fetus having chromosomal abnormalities.
Chromosome defects are thought to cause over 50 per cent of miscarriages, with this number increasing with maternal age. Dr Munne explained that 'PGD remains a viable option for many couples who are at risk of passing on certain genetic diseases to their children or who have been unsuccessful with assisted reproduction to help increase their chance of having a healthy baby'.