Featured Research

from universities, journals, and other organizations

First babies born from genetic screening study

Date:
October 18, 2010
Source:
European Society of Human Reproduction and Embryology
Summary:
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.

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.

Related Articles


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:

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.


Story Source:

The above story is based on materials provided by European Society of Human Reproduction and Embryology. Note: Materials may be edited for content and length.


Cite This Page:

European Society of Human Reproduction and Embryology. "First babies born from genetic screening study." ScienceDaily. ScienceDaily, 18 October 2010. <www.sciencedaily.com/releases/2010/10/101015105931.htm>.
European Society of Human Reproduction and Embryology. (2010, October 18). First babies born from genetic screening study. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2010/10/101015105931.htm
European Society of Human Reproduction and Embryology. "First babies born from genetic screening study." ScienceDaily. www.sciencedaily.com/releases/2010/10/101015105931.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Raw: Paralyzed Marine Walks With Robotic Braces

Raw: Paralyzed Marine Walks With Robotic Braces

AP (Nov. 21, 2014) Marine Corps officials say a special operations officer left paralyzed by a sniper's bullet in Afghanistan walked using robotic leg braces in a ceremony to award him a Bronze Star. (Nov. 21) Video provided by AP
Powered by NewsLook.com
Milestone Birthdays Can Bring Existential Crisis, Study Says

Milestone Birthdays Can Bring Existential Crisis, Study Says

Newsy (Nov. 21, 2014) Researchers find that as people approach new decades in their lives they make bigger life decisions. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins