Baby gene tests safety should be checked

Apr 26 2005

Experts are warning that the long-term safety of screening embryos for genetic diseases is going unchecked.

Preimplantation genetic diagnosis (PGD) is a way of checking that an embryo is free of inherited diseases before it is put into the womb to grow.

PGD is a relatively new procedure and was first introduced in 1990 as an experimental procedure. It involves removing a cell from an embryo when it is around three-days old and experts are saying that not all babies born after PGD are being followed up to check for any adverse effects this might have.

Since 1990 it is estimated that more than 1,000 babies have been born following PGD and licences have been granted for PGD to screen for the genetic form of cystic fibrosis and Huntington's disease.

In November 2001, the Human Fertilisation and Embryology Authority (HFEA) agreed on conditions in which PGD could be used under the Human Fertilisation and Embryology Act (1990) and in line with the results of a public consultation on the acceptability of PGD.

It is said that PGD can also be used to check for an inherited form of bowel cancer called familial adenomatous polyposis and that embryos can also be selected purely because they are a tissue match for a sick sibling.

There are eight centres in the UK that currently offer PGD to couples from families with a strong history of inherited diseases and about 100 cycles of PGD are carried out there each year. Worldwide there are about 1,000, according to the HFEA.

Professor Peter Braude, professor of Obstetrics and Gynaecology at Kings College London, one of the UK centres offering PGD, questioned why all PGD centres were not all following up PGD babies. Braude says they follow up all of our babies at two month, six months, one year, two years and five years which is very important. Braude says there is a move for a European PGD register.

According to other experts the technique appears to be safe, as yet, children born after PGD have not shown any greater abnormalities than children born naturally.

A recent study by the Reproductive Institute of Chicago study looked at 754 babies born after in-vitro fertilisation pregnancies where PGD was used and found they were no more likely to suffer birth defects than babies born after natural pregnancies.

The HFEA says they recognise the importance of following up children who have been screened with PGD but it was not currently a legal requirement or standard practice. Current confidentiality rules make it impossible for the HFEA to share its data on PGD children with the relevant interested parties and specialists.

That situation might change when there is a review of the Human Fertilisation and Embryology Act later this year.