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 How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>