The foetuses are killed by lethal injection

The Office for National Statistics recorded that 49 foetuses were destroyed in the womb by lethal injection in 2001.

The majority of these foetuses were normal and healthy, and most of the women involved had become pregnant after fertility treatment.

In two cases, sets of quads were reduced to just one foetus, and in five cases triplets had two of the foetuses killed.

This kind of feticide is unacceptable Jack Scarisbrick, Life

IVF and other techniques greatly increase the risk of having a multiple birth - which exposes the mother to a higher risk, particularly if she is older.

The Human Fertilisation and Embryology Authority (HFEA) recommends that a maximum of two fertilised embryos be put back into a woman, meaning that there is a very small risk of more than two babies.

However, many IVF specialists argue that a two-embryo limit is too low, particularly in older women who find it harder to conceive.

The HFEA says that three embyros can be used in "exceptional circumstances".

Eight foetuses

"Selective reductions" are usually suggested by doctors in cases in which women are carrying large numbers of foetuses.

We will be enforcing the limit on the number of embryos far more tightly in future Spokesman, HFEA

This was highlighted by the case of UK woman Mandy Allwood, who became pregnant with eight babies, opted against selective reduction to a smaller number, and ended up losing all eight.

Some doctors are known to be ethically opposed to carrying them out in any circumstances other than dire risk to all the foetuses or the health of the mother.

The termination is carried out by injecting a poison into the heart of the foetus.

Pro-life campaigners say it is particularly perverse for women undergoing IVF who long for a child to then destroy a viable foetus.

'Cynical'

Jack Scarisbrick, from the pressure group Life, said: "This kind of feticide is unacceptable.

"It's utter cynicism to deliberately manufacture a human being which you then deliberately destroy."

A spokesman for the Human Fertilisation and Embryology Authority, which regulates fertility clinics in the UK, said that reducing the incidence of multiple pregnancies in the first place was the way to reduce the number of these procedures taking place.

She said: "We will be enforcing the limit on the number of embryos far more tightly in future.