All IVF embryos should be checked for genetic defects, conference is t
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《英国医生杂志》
All embryos resulting from in vitro fertilisation (IVF) should be routinely checked for genetic abnormalities before implantation, a conference on human genetics heard this week.
New evidence indicates that screening embryos vastly improves the chances of producing a healthy baby in women aged over 35 who undergo IVF.
Dr Yury Verlinsky, a leader in the field of preimplantation genetic diagnosis and director of the Reproductive Genetics Institute, Chicago, told the sixth international symposium on preimplantation genetic diagnosis in London that the findings should lead to only normal embryos being used in treatment.
In a study of 709 couples Dr Verlinsky抯 team found that the percentage of couples who were able to have a baby after preimplantation genetic diagnosis was 81%, compared with 11% of couples who didn抰 undergo diagnosis. By screening embryos Dr Verlinsky ensured that only embryos with a good chance of success were implanted.
Dr Verlinsky said: "Forty to seventy per cent of embryos have chromosomal abnormalities. So by selecting to transfer only a normal embryo we fulfil our dreams to have a healthy child."
Preimplantation genetic diagnosis was first introduced in 1990, and in the United Kingdom its use is restricted. The UK Human Fertilisation and Embryology Authority has allowed the screening technique for people who carry genes for cystic fibrosis, Huntington抯 disease, or familial adenomatous polyposis, an inherited form of bowel cancer.
Professor Robert Edwards, the pioneer of IVF, agreed with Dr Verlinsky. "The time has come that when we transfer an embryo we should only be transferring normal embryos. The days of implanting abnormal embryos are gone," he told the conference.
But Dr Peter Brinsden, medical director of Bourn Hall Clinic, Cambridge, which specialises in IVF, said: "The big problem with screening embryos is the extra cost. IVF costs enough in its own way."
Dr Verlinsky said it was important to balance the $1000 cost ($550; �800) of using screening techniques to produce a healthy baby against the expense of looking after a sick child. As preimplantation genetic diagnosis increases the success rate of IVF, women would also need fewer cycles of treatment, therefore bringing down the overall cost.
Dr Edwards agreed: "Our politicians need to realise that preimplantation genetic diagnosis is here and that it has to be funded. If you have a sick child, has to be paid for by the health service. If you can legitimately and legally make sure that birth is normal, then we should do it."
Dr James Watson, president of Cold Spring Harbor Laboratory, New York, who is best known for his part in the discovery of the structure of DNA, also spoke at the conference.
Dr Watson, along with the other two scientists, Edwards and Verlinsky, agreed that couples should be allowed to choose a child抯 sex. He attacked as "absurd" the situation in the UK where, under Human Fertilisation and Embryology Authority regulations, parents are prevented from choosing the sex of their child.
"It is perfectly valid; some women want daughters, so let them have them. It is absurd that the UK makes it illegal. It is the big brother attitude of the upper middle classes who think they know best; it is so pompous, and socialism at its worst," he said.(Rebecca Coombes)
New evidence indicates that screening embryos vastly improves the chances of producing a healthy baby in women aged over 35 who undergo IVF.
Dr Yury Verlinsky, a leader in the field of preimplantation genetic diagnosis and director of the Reproductive Genetics Institute, Chicago, told the sixth international symposium on preimplantation genetic diagnosis in London that the findings should lead to only normal embryos being used in treatment.
In a study of 709 couples Dr Verlinsky抯 team found that the percentage of couples who were able to have a baby after preimplantation genetic diagnosis was 81%, compared with 11% of couples who didn抰 undergo diagnosis. By screening embryos Dr Verlinsky ensured that only embryos with a good chance of success were implanted.
Dr Verlinsky said: "Forty to seventy per cent of embryos have chromosomal abnormalities. So by selecting to transfer only a normal embryo we fulfil our dreams to have a healthy child."
Preimplantation genetic diagnosis was first introduced in 1990, and in the United Kingdom its use is restricted. The UK Human Fertilisation and Embryology Authority has allowed the screening technique for people who carry genes for cystic fibrosis, Huntington抯 disease, or familial adenomatous polyposis, an inherited form of bowel cancer.
Professor Robert Edwards, the pioneer of IVF, agreed with Dr Verlinsky. "The time has come that when we transfer an embryo we should only be transferring normal embryos. The days of implanting abnormal embryos are gone," he told the conference.
But Dr Peter Brinsden, medical director of Bourn Hall Clinic, Cambridge, which specialises in IVF, said: "The big problem with screening embryos is the extra cost. IVF costs enough in its own way."
Dr Verlinsky said it was important to balance the $1000 cost ($550; �800) of using screening techniques to produce a healthy baby against the expense of looking after a sick child. As preimplantation genetic diagnosis increases the success rate of IVF, women would also need fewer cycles of treatment, therefore bringing down the overall cost.
Dr Edwards agreed: "Our politicians need to realise that preimplantation genetic diagnosis is here and that it has to be funded. If you have a sick child, has to be paid for by the health service. If you can legitimately and legally make sure that birth is normal, then we should do it."
Dr James Watson, president of Cold Spring Harbor Laboratory, New York, who is best known for his part in the discovery of the structure of DNA, also spoke at the conference.
Dr Watson, along with the other two scientists, Edwards and Verlinsky, agreed that couples should be allowed to choose a child抯 sex. He attacked as "absurd" the situation in the UK where, under Human Fertilisation and Embryology Authority regulations, parents are prevented from choosing the sex of their child.
"It is perfectly valid; some women want daughters, so let them have them. It is absurd that the UK makes it illegal. It is the big brother attitude of the upper middle classes who think they know best; it is so pompous, and socialism at its worst," he said.(Rebecca Coombes)