Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First birth using PGD to save baby from rhesus blood disease

20.01.2005


Australian researchers (Thursday 20 January) announced that they have used pre-implantation genetic diagnosis (PGD) to avoid a couple having a baby suffering from rhesus factor[1] disease – the potentially fatal condition caused by incompatibility between a baby’s blood and that of its mother.



Their pioneering work resulted in the birth of a healthy baby girl in November 2003 to a couple who had previously had one child severely affected by Rh disease.

Writing in Europe’s leading reproductive medicine journal Human Reproduction[2], the research team from the Royal North Shore Hospital and Sydney IVF, state that this is the first reported case of an unaffected pregnancy using PGD to prevent Rh disease.


In Caucasian populations about 17% of pregnant women are RhD negative (RhD-). Of these, around 60% will have a baby who has inherited RhD positive (RhD+) blood from its father. During the first pregnancy, the mother recognises the baby’s blood as ’foreign’ and may develop antibodies against it – usually at delivery. This is called alloimmunization. It doesn’t harm the baby, but it puts future pregnancies involving an RhD+ baby at risk because the antibodies the mother made during her first pregnancy may cross the placenta to her unborn child. The result can be haemolytic disease of the fetus or newborn, which, in extreme cases, causes severe anaemia in the fetus, stillbirth or the death of the baby shortly after birth.

Between one and two in a hundred RhD negative women are at risk of alloimmunization during or immediately after a pregnancy. Over the past 35 years this figure has been cut to about 0.2% by the use of anti-D injections administered in the 28th and 34th week of pregnancy.

However, according to lead researcher Dr Sean Seeho, this still results in a significant number of babies in Australia[3] being affected by RhD alloimmunization because there are around 25,000 RhD+ babies born to about 45,000 RhD- mothers annually. And this excludes women sensitized through other events such as miscarriages, abortions and invasive procedures. In countries where anti-D is not available or guidelines may not be carefully followed, the risk of RhD alloimmunization is higher than in Australia.

"We can treat affected babies before birth by intravascular transfusions and achieve a survival rate of between 70% and 95% depending on circumstances, but that means there is still a significant death rate associated with the condition," said Dr Seeho, who is a research fellow at the Maternal Fetal Medicine Unit at the Royal North Shore Hospital and a clinical lecturer at the University of Sydney.

"A couple who have had a significantly affected pregnancy are faced with the dilemma of whether or not to attempt further pregnancies, and the tendency for Rh disease to worsen with each subsequent RhD incompatible pregnancy plays a major part in the decision. That was the situation for our couple where their second child had developed serious side effects as a result of alloimmunization."

Dr Seeho said that PGD has mainly been used since its introduction in 1990 to detect single gene diseases such as cystic fibrosis, or to screen for chromosomal disorders. But, in this case the research team used the technique to select an RhD- embryo from among a number of embryos produced after the mother underwent IVF treatment. The technique involves the biopsy and testing of a single cell from early developing embryos with an unaffected embryo subsequently being transferred to the woman’s womb.

"Although the use of PGD to manage Rh disease has been previously published, to our knowledge this is the first case of an unaffected RhD- baby being born to an RhD- alloimmunized mother using PGD," said Dr Seeho.

He envisaged that PGD for Rh disease would be most likely to be used in future by couples where there had been a previous severely affected pregnancy involving, for example, a stillbirth, or where the fetus had needed an intravascular transfusion.

"Unfortunately, there are currently very few IVF units in Australia and most probably worldwide that could offer PGD for affected couples due to lack of expertise in PGD or the fact that they don’t offer PGD at all. There are also possible financial barriers because it involves IVF.

"However", he concluded, "PGD does provide an approach for selected couples who face a high risk of this distressing condition and this latest use also underlines the growing potential of PGD for managing other conditions such as sex-linked disorders, single gene defects and chromosomal aberrations."

[1] Rh factor: After the A, B, AB and O blood groups, rhesus factor is the most important. The gene making a person rhesus positive (RhD+) is called D and is present in most people. When an RhD+ father produces an RhD+ baby in a rhesus negative (RhD-) mother, the baby’s red blood cells act as antigens causing the mother to produce antibodies against them. The antigens do not normally reach the mother’s blood until labour so are unlikely to harm the first pregnancy, but in subsequent pregnancies the levels of antibodies rise rapidly to a point at which they can destroy the baby’s red blood cells, causing severe problems and even the death of the fetus or newborn. Anti-D immunization of the mother can normally prevent the problem. About 16% of Europeans are RhD-. In the USA the figure is 15%, although only 5 to 10% of African Americans are RhD-. Among Africans and Asians, less than 1% are RhD-.

[2] The role of preimplantation genetic diagnosis in the management of severe rhesus alloimmunization: first unaffected pregnancy. Human Reproduction. Doi:10.1092/humrep/deh624.

[3] In England and Wales an estimated 62,000 babies RhD+ babies are born to RhD- mothers every year. Of these, around 500 develop haemolytic disease of the newborn (HND) and 25-30 die of it. About 15 will have permanent developmental problems and 30 will have minor developmental problems. Source: Omar Ali, Hospital Pharmacist, March 2003. In the USA around 4,000 babies are born each year with HND.

Margaret Willson | EurekAlert!
Further information:
http://www.eshre.com

More articles from Life Sciences:

nachricht Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

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

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>