Articles
Register for Dr. Cathy Allen: Will IVF work for a Particular Patient? The Answer may be found in her blood
Wednesday 1 July 2009
25th annual conference of the European Society of Human Reproduction and
Embryology
NB: this is the subject of a news briefing by Dr. Cathy Allen at 09.30 hrs (CEST)
on Wednesday 1 July [Rooms R & S, First Floor]
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.
The researchers found that the peripheral blood gene expression ‘signature’
(also known as the transcriptome) before IVF was predictive of IVF outcome. This
finding demonstrates the power of high-dimensional technology in biomarker
discovery, and highlights the potential for developing clinically useful tools,
they say.
One of the most difficult decisions for patients who have had unsuccessful IVF
treatments is whether they should undergo further attempts at IVF, or if there
are ways to optimise chances of success. The researchers hope that the results
generated by this work will lead to the development of a test to aid in IVF
decision-making. They say that their work will help to identity biomarkers that
can identify events occurring at implantation, the maintenance of pregnancy and
successful or unsuccessful pregnancy outcome.
“IVF technology has advanced tremendously over the past three decades, yet
success after IVF remains an unpredictable outcome,” said Dr. Allen. “Our work
will help understand whether the implantation of embryos is influenced by the
constantly changing expression of human genes.”
Previous studies in the field of gene-expression have focused on single genes as
opposed to genome-wide screening of all the human genes with high density DNA
microarrays, as used by Dr. Allen and her team. The advent of tools like
microarrays that can simultaneously probe for up to 29,000 genes has radically
changed scientific approaches to this type of research. “It’s like looking at
how a team of players perform together rather than focusing on the individual
players,” said Dr. Allen.
“We intend to look further at the most significant genes we have identified as
being important in this field in order to be able to understand their exact
biological role in reproductive function. We hope that our work will lead to the
development of a clinically useful tool to help doctors counsel their patients
in the difficult decision-making involved in IVF,” she said.
Abstract no: O-269 Wednesday 14.15 hrs CEST (Elicium 1)
Further information:
In English and French:
Mary Rice:
Te;: +33(0)3 21 82 54 44
Mobile: +33(0)6 68 93 06 50
Email: Mary@mrcommunication.org
In English:
Emma Mason
Tel: +44 (0) 1376 563090
Mobile: +44 (0) 7711 296n986
Email: wordmason@mac.com
In Dutch and English:
Peter Vermij
Tel: +31-20 618 3420
Mobile: +31 6 290 300 43
Email: peter@vermij.com
Press Office: (Sunday 28 June – Wednesday 1 July)
Mary Rice, Emma Mason, Peter Vermij, Hanna Hanssen
Tel: + 31 (0)20 544 5813 and 31(0)20 544 5814
Fax: + 31 (0)20 544 5815
