The scientists examined 400 fertilised eggs generated by women with a very poor reproductive history and with an average age of 42 who were undergoing IVF because of being unable to conceive or to maintain a pregnancy. They found that more than half of all the eggs produced by these women had chromosomal abnormalities, and therefore the resulting embryos were also chromosomally abnormal. Some of the women had a tendency to produce eggs that were extremely abnormal and carried multiple chromosome errors. This could explain the poor reproductive history of these women, the scientists say.
"But where we could find fertilised eggs free of chromosomal abnormalities, the resulting embryos were also normal and their transfer to the mother led to pregnancies," said Dr. Fragouli. "Results suggest that the use of this technique will improve IVF success rates for poor prognosis patients. It is also likely to achieve a reduction in congenital abnormalities such as Down's syndrome, as well as a reduction in the frequency of spontaneous miscarriage."
The incidence of chromosomal abnormalities in human eggs is closely related to maternal age, and can affect more than 60% of all eggs in women over 40 years of age. Being able to select the right egg can not only lead to more successful IVF, but also enhance the use of single embryo transfer, especially in countries where embryo testing is forbidde
|Contact: Mary Rice|
European Society for Human Reproduction and Embryology