生殖補助技術の安全性

最近体外受精をはじめ生殖補助技術により児の異常が増えるという見解が出されているので、英国のHFEAは英国で出産した子供の長期的な影響を調べることにした。顕微授精では新生児異常がわずかに増えるとされ、また卵の凍結により遺伝子の活動に影響が出ると考えられている。

Tuesday, 22 October, 2002, 07:43 GMT 08:43 UK
IVF safety to be examined

A major study is to be carried out to assess whether children born using artificial fertility techniques face health problems in later life.
The Human Fertilisation and Embryology Authority (HFEA) is to consider how best to examine the long-term effects on children born using IVF (in vitro fertilisation) techniques. In total, 68,000 IVF children have been born since the technique was pioneered in 1978. However, it has not been decided how many, if any of these children will be studied.
The HFEA and the Medical Research Council (MRC) have established a joint working party, chaired by senior epidemiologist Professor Catherine Peckham, to decide how to carry out the research.
A number of overseas studies published this year have led to concerns that some forms of IVF treatment may be unsafe.
ICSI fears
A technique called intra-cytoplasmic sperm injection (ICSI) where a single sperm cell is injected directly into an egg has prompted particular concern.
ICSI is used to help men with low sperm counts father a child, but it bypasses many of the body's natural mechanisms for weeding out unfit sperm which may carry damaged genetic information.
Research presented at a conference of the European Society of Human Reproduction and Embryology this summer concluded that the technique resulted in a slightly increased chance of birth defects.
An HFEA spokeswoman said: "Whilst there is no evidence to suggest an increase in the number of birth defects in children born from normal IVF, there may be a slight increase in abnormalities among children born as a result of ICSI.
"The risk is still very small but we think it is worth taking a closer look."
The spokeswoman added: "There is no need for people who have had children with fertility treatment to be worried.
"It is simply that there is a lot we don't know and we are carrying out this study to try and find some answers."
Frozen embryos
Some experts are also worried about the safety of fertility techniques that use frozen embryos - responsible for about 7,000 babies in the UK.
Lord Winston, professor of fertility studies at Imperial College School of Medicine, said his laboratory at Hammersmith Hospital in west London plans to publish reserach showing that freezing embryos affects the normal activity of vital genes.
He told The Independent newspaper: "Basic functions such as growth, respiration and metabolism are regulated by genes, and if you change the way those genes are expressed - even temporarily - during times of rapid development, such as an embryo, you may well expect to see changes in the way the embryo develops."