Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First babies born from genetic screening study

18.10.2010
Births in Italy and Germany from eggs tested by CGH

Two women taking part in the world's first controlled study of a comprehensive genetic screening test before IVF have given birth to healthy babies.

The babies, twin girls born in Germany in June and a singleton boy born in Italy in September, are the first deliveries in a pilot study of comparative genomic hybridisation (CGH) by microarray, a new method of screening oocytes for IVF for a full range of chromosomal disorders.

Dr Cristina Magli, embryologist at the SISMER Centre in Bologna, one of the two centres taking part in the trial, said: " All the babies and their mothers are doing very well in terms of weight and overall developmental performance."

The births, as well as several ongoing pregnancies in the study group, are the final stage in the "proof of principle" that the screening of oocytes and embryos before transfer in IVF can increase birth rates; both these pregnancies were derived from oocytes whose complete chromosomal status had been assessed by microarray CGH.

The study, which was conducted in Bologna, Italy, and Bonn, Germany, was designed and organised by a task force of ESHRE to determine the clinical value of CGH as a non-subjective means of genetic screening before embryo transfer.

"We have learnt from more than 30 years of IVF that many of the embryos we transfer have chromosome abnormalities," explains ESHRE's chairman Luca Gianaroli. "Indeed, it's still the case that two out of every three embryos we transfer fail to implant as a pregnancy, many of them because of these abnormalities.

"The whole world of IVF has been trying to find an effective way of screening for these abnormalities for more than a decade, but results so far have been disappointing with the technology available. Now we have a new technology in array CGH and our hopes are that this will finally provide a reliable means of assessing the chromosomal status of the embryos we transfer."

The microarray CGH technique as evaluated in the ESHRE study 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 (known as the polar body) is taken from an oocyte at fertilisation, and so does not require biopsy of a cell from a developing embryo for its analysis

Earlier chromosome tests were on cells biopsied from growing embryos and did not necessarily reflect the total status of the embryo (because of chromosome "mosaicism"); polar body analysis removes this potential problem

Other CGH tests on biopsies from five-day-old embryos require several days to deliver complete results - and thus require the freeze-storage of the embryo before it can be transferred; polar body CGH can be done in real time and does not require freezing

At the everyday clinical level, polar body CGH is likely to have two more important consequences: first, because the analysis is performed on oocytes and not on embryos, countries like Germany which outlaw embryo analysis and freezing will now have at their disposal a reliable method of preimplantation genetic screening; and second, because the chromosomal status of the transferred embryo can be accurately predicted (with no more than a 10 per cent error rate as found in the ESHRE study), the reduction of multiple pregnancies in IVF by single embryo transfer will become more attractive.

In the short term, the IVF patients most likely to benefit from preimplantation screening by polar body CGH are those of an older maternal age (over 37 years), those with a record of unsuccessful IVF, and those with a history of miscarriage; all these conditions are associated with a higher than average rate of embryonic chromosomal abnormality.

"The study has already caused huge interest in the scientific and clinical community," says Dr Magli, "and we are very proud to announce these results. It is the first time that a scientific society like ESHRE has organised a study to determine the clinical value of a technique which could prove a revolution in IVF."

The next step for ESHRE will be to upgrade the pilot study into a large-scale international clinical trial, which is planned to start in 2011.

Notes for editors

1. The pilot study was performed at the SISMER centre in Bologna, Italy (Professor Luca Gianaroli, chairman of ESHRE, and Dr Cristina Magli), and the University of Bonn, Germany (Dr Markus Montag and Professor Hans van der Ven). All data from the study were independently collected and analysed by Sjoerd Repping from the Academic Medical Centre in Amsterdam.

2. Results of validating the accuracy of the pilot study analysis were presented at ESHRE's 2010 annual meeting in Rome. They showed that 23-chromosome testing of both polar bodies with array CGH can be completed within 12-13 hours (thereby allowing for fresh transfer), and that the reliable identification of the chromosomal status of an oocyte is possible in almost 90 per cent of attempts.

3. The average age of the patients in the study was 40.0 years, an age usually associated with a poor outcome in IVF.

4. The CGH technique allows visualisation of numerical loss or gain in each of the 23 chromosome pairs of a cell, reflected in array patterns above or below a normal reference range. A numerical gain at chromosome 21, for example, ("trisomy 21") is consistent with risk of Down's syndrome.

5. Two polar bodies are formed as an oocyte reaches maturity. They each contain by-products from the maturation process. The first polar body is extruded at the time of ovulation (when mature), and the second at fertilisation.

ESHRE is the world's leading professional society in reproductive science and medicine, with almost 6000 members throughout the world.

More information on this press release and further comment from Professor Gianaroli is available from ESHRE's central office

Hanna Hanssen | EurekAlert!
Further information:
http://www.eshre.eu

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>