Amsterdam, The Netherlands: For the first time, researchers have been able to identify genetic predictors of the potential success or failure of IVF treatment in blood. Dr. Cathy Allen, from the Rotunda Hospital, Dublin, Ireland, told the 25th annual conference of the European Society of Human Reproduction and Embryology today (Wednesday 1 July) that her research would help understand why IVF works for some patients but not for others.
Previous work in this area has looked at gene profiles in such tissues as the uterine lining, but Dr. Allen and her team chose to examine the gene expression patterns in RNA extracted from peripheral (circulating) blood, an easily accessible biological sample. Blood samples were taken at eight different stages during the period around conception and the early stages of the IVF cycle. Five of these samples came from women who achieved clinical pregnancies, three from those who had implantation failure, and three from subfertile women who conceived spontaneously. Analysis showed that 128 genes showed a more than two-fold difference in expression in early clinical pregnancy compared with a non-pregnant state.
The molecular pathways that were most over-represented in this expression were concerned with angiogenesis (the growth of new blood vessels), endothelin signalling (blood vessel constriction), inflammation, oxidative stress (damage to cell structures), vascular endothelial growth factor (signalling processes in blood vessel growth), and pyruvate metabolism (the supply of energy to cells). "All these processes are important in the achievement and maintenance of pregnancy," said Dr. Allen.
"We found that the gene expression profiles in blood of patients at the time of pituitary down-regulation showed interesting patterns of gene clustering. Over 200 genes were differentially expressed in patients who went on to achieve an IVF pregnancy compared with those who did not," she said.
|Contact: Mary Rice|
European Society for Human Reproduction and Embryology