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Last Updated: Wednesday, 18 August, 2004, 16:27 GMT 17:27 UK
Embryo screening 'no health risk'
IVF
The parents in these cases underwent fertility treatment
Carrying out tests on embryos to screen for genetic disorders, does not harm their health, a large scale review of the procedure has found.

The Reproductive Institute of Chicago study looked at 754 babies born after IVF pregnancies where preimplantation genetic diagnosis was used.

It found they were no more likely to suffer birth defects than babies born after natural pregnancies.

The research is published in the journal Fertility and Sterility.

Preimplantation genetic diagnosis, or PGD, was first introduced in 1990 as an experimental procedure.

This new study further supports our policy decision and means that all potential parents who use PGD to avoid serious disease can be reassured that the test is not harming their babies
Human Fertilisation and Embryology spokeswoman
It involves removing a cell from an embryo at the eight-cell stage of development, when it is around three-days old, and testing it for genetic disorders, such as cystic fibrosis, so that an unaffected embryo can be implanted into the mother's womb.

It is now an established technique, and more than 1,000 babies have been born after PGD.

The Human Fertility and Embryology Authority last month gave the go-ahead for the technique to be used so that embryos could be selected purely because they are a tissue match for a sick sibling.

In the past, the HFEA had always said the child resulting from the selected embryo had to see a direct benefit from the procedure.

It had restricted the use of the procedure because of fears removing a cell from an embryo could affect its later development.

Maternal age

The US research looked at families treated at three centres in Chicago, New Jersey and Bologna, Italy, accounting for around three-quarters of PGD babies born so far

It was found the overall rate of birth defects was the virtually the same as that seen in the general population, 0.4% for abnormalities such as Down's Syndrome or spina bifida and between 2 to 4% for conditions such as cleft palate.

Previous research had suggested PGD babies had slightly higher birth defect rates, but it is now thought this was a statistical anomaly, caused by the small number of cases studied.

Researchers say any slight increase that is seen is likely to be linked to the age of the mother.

Women who have the treatment tend to be older than the norm, and maternal age is recognised as being the main risk factor for birth defects,

A spokeswoman for the HFEA, which recently extended its policy to allow PGD with tissue typing to create babies who could provide compatible stem cells for transplant to very sick siblings, said: "This decision was based on the latest available evidence which suggested that the embryo was at minimal risk from the biopsy procedure itself.

"This new study further supports our policy decision and means that all potential parents who use PGD to avoid serious disease can be reassured that the test is not harming their babies."


SEE ALSO:
Baby gender selection ruled out
12 Nov 03  |  Health


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