21 October 2010

Chromosome Testing in Developing IVF Embryo

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IVF Australia

Australian scientists are in the final stages of validating the new method of comprehensive screening of IVF eggs and embryos for the full range of chromosomal disorders, a service that will be available within weeks at Melbourne IVF, with IVFAustralia and Queensland Fertility Group to follow.

“Single cell microarray testing enables us to identify and test every chromosome in a developing embryo which is a significant advance on current technology where only 8-10 chromosomes could be tested. The microarray test is rapid and results are available within 36 hours which now means we can transfer an unaffected fresh embryo, offering higher pregnancy rates for IVF patients,” said Dr Leeanda Wilton, Scientific Director of Pre-Implantation Genetics for Melbourne IVF, IVFAustralia and Queensland Fertility Group.

The European Society of Human Reproduction (ESHRE) announced this week the birth of the first babies resulting from the world’s first study on comprehensive genetic screening of eggs before IVF.

“Whilst the ESHRE report is encouraging we know that it is limited to testing errors that occur in eggs. We will use this new microarray comparative genomic hybridisation (aCGH) technique on embryos as it is well documented that many additional errors occur in the first three days of an embryo’s development,“ said Dr Wilton.

 “This microarray technique builds on the ground breaking technology developed at Melbourne IVF ten years ago where we proved testing for only 8 chromosomes is inadequate as up to 30 % of embryos we thought were normal had an error on another chromosome that we were not able to test for,” she said.

“The new technique builds on the former CGH technology which was time consuming. The long wait for results meant that embryos had to be frozen and transferred at a later stage” Dr Wilton explained.

The microarray CGH technique to be used by Dr Wilton’s team has several advantages over other methods:

* CGH tests all 23 pairs of chromosomes in a cell, and not just a limited number (as in former methods)
* The cell tested is taken from an early stage embryo at the time when the maximum number of chromosome disorders are evident
* Results will be delivered within 36 hours enabling fresh transfer of unaffected embryos.

The IVF patients most likely to benefit from this technique are women over 38 years of age, those with known hereditary chromosomal conditions, a record of unsuccessful IVF, and those with a history of miscarriage. All of these conditions are associated with a higher than average rate of embryonic chromosomal abnormality.

For more information contact Nicole Phillips - 0408 280 499

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