Forum Bioethik July 02, 2002

1.       Doctors: Diagnostic Method Can Cut Miscarriage Rate
2.       New test shows promise in weeding out genetically damaged sperm
3.       AstraZeneca funds twin registry in exchange for information

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Doctors: Diagnostic Method Can Cut Miscarriage Rate
Mon Jul 1, 9:46 AM ET
VIENNA (Reuters) - Doctors could reduce the rate of miscarriages in high
risk women by analyzing embryos for genetic defects before transferring them
into the womb during IVF treatment, fertility experts said on Monday.
Carmen Rubio of the Valencia Institute for Infertility in Valencia, Spain
told a fertility conference that chromosomal abnormalities are an important
cause of repeated miscarriages and failure of the embryo to implant in the
But a technique called preimplantation genetic diagnosis (PGD), in which a
single cell is removed from the embryo and examined, can detect the embryos
which are most likely to result in a miscarriage.
It allows doctors to select the best embryos which are most likely to result
in a normal pregnancy and a healthy baby.
"Our study shows that, in some couples, suffering from repeated unexplained
miscarriages or implantation failure, chromosomal abnormalities in the
embryo can be the cause of the problem," Rubio said.
The technique could also help to identify couples who have an increased risk
of producing abnormal embryos, she added.
PGD is usually done when the embryo has reached the six to eight-cell stage.
One cell is removed and its DNA is analyzed to determine if the embryo is
likely to develop a genetic disease.
When Rubio and her colleagues used PDG on 71 women who had suffered from
repeated miscarriages and 42 other women whose embryos failed to implant in
the womb, they found that the number of abnormal embryos was a third higher
than in a control group of fertile women.
Rubio told the meeting of the European Society of Human Reproduction and
Embryology (ESHRE) in Vienna that her team achieved similar pregnancy rates
in all three groups after transferring only the normal embryos to the womb.



New test shows promise in weeding out genetically damaged sperm
Mon Jul 1,12:23 PM ET
Associated Press
By EMMA ROSS, AP Medical Writer
VIENNA, Austria - A new method that allows fertility doctors to select
genetically healthy sperm raises the possibility that they will soon be able
to routinely pick good sperm, giving them a better chance of success in
creating test tube babies.
Chromosome defects in sperm are more common in infertile men, but are hard
to identify. Most fertility clinics select which sperm to inject into the
egg by checking their shape and the way they move.
"This is the first time there is a simple, non-invasive technique that can
be of practical use to weed out sperm with the wrong number of chromosomes,"
said Arne Sunde, an embryo scientist from Trondheim University in Norway.
"The technique itself is so easy that it lends itself to routine work, so we
can introduce it as an integral part of a fertility service."
"We can do it with a very complicated technique which also has side
effects," said Sunde, who was not connected with the research. "This mimics
nature. I can't foresee any negative effects; only positive effects."
The test, described Monday by infertility specialist Gabor Huszar at a
meeting of the European Society of Human Reproduction and Embryology in
Vienna, uses the same method that nature does in determining which sperm can
fertilize an egg.
As sperm matures, the sperm membrane changes and as it does it develops a
receptor that recognizes the shell of the egg. That maturing process is
associated with earlier normal chromosomal development.
In normal reproduction, only those sperm that develop this receptor are able
to fertilize an egg.
Huszar discovered that healthy sperm also develop a receptor that recognizes
a substance called hyaluronic acid, found in the female reproductive tract.
He discovered that the formation of the two receptors are linked.
In infertile men, a large proportion of the sperm do not mature. Maturity is
judged by correct chromosome development and the development of the
Doctors cannot tell the difference between mature and immature sperm when
they are selecting a single sperm to inject into an egg.
"The embryologist just picks up the best looking sperm and injects it in the
egg, so you suddenly get a population of sperm which fertilizes that could
never have fertilized before," said Huszar, a research professor of
obstetrics and gynecology at Yale University School of Medicine.
While sperm injection has made it possible for hundreds of thousands of
infertile men to become fathers, it also allows chromosome defects to get
through that normally would not.
Although there is no proof, experts are concerned that the defects inherited
by children of infertile men could increase the risk of cancer,
developmental problems or genetic linked diseases later in life.
Huszar's invention involves fixing blobs of hyaluronic acid to a regular
petri dish. Sperm are then sprinkled into the dish and they start swimming.
The sperm that have developed the receptor for hyaluronic acid are drawn to
the blobs, while the others swim right past.
The sperm that go to the blobs can then be taken out of the dish and
injected into an egg.



AstraZeneca funds twin registry in exchange for information

Wed Jun 26,12:09 PM ET

Associated Press

STOCKHOLM, Sweden - Drug maker AstraZeneca PLC said Wednesday that it has
agreed to fund a comprehensive Swedish database on twins in exchange for
access to statistical information from the registry.

The Karolinska Institute in Stockholm started collecting data on a voluntary
basis from Swedish twins in the 1950s. The registry  one of the largest of
its kind  now contains information ranging from tobacco habits to medical
histories of about 140,000 twins.

AstraZeneca will use the information, which will not include identities, to
study several diseases, including cancer, spokeswoman Maria Anvret said.

The history of identical twins, for example, could help researchers separate
genetic from environmental links to a certain disease.

"If one twin is exposed to different environmental experiences than the
other, researchers can explain more precisely why one individual suffers
from a disease while the other does not," she said.

Anvret said AstraZeneca would fund the maintenance of the database for at
least five years. Both AstraZeneca and Karolinska declined to release
financial details.

Nancy Pedersen, who is in charge of the twin registry at the institute, said
some of the funding could be used to add genetic information to the database
by collecting blood samples from twins.

The current information in the database is based on personal surveys, she

The Karolinska Institute accounts for 40 percent of all medical research at
universities in Sweden and chooses the winner of the annual Nobel Prize in

AstraZeneca, which was formed in 1999 through the merger ( news - web sites)
of Astra of Sweden and the Zeneca Group of Britain, has 54,000 employees

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