The biggest shake-up of Britain's fertility laws for 15 years could usher in an era when couples may be able to choose the sex and possibly the genes of their "designer" babies.

The Government highlighted more than 70 fertility issues yesterday that are to be totally reappraised in its proposed update of the 1990 Human Fertilisation and Embryology Act - a law formulated after the Warnock Report of 1985.

For the first time, ministers are contemplating the possibility of allowing scientists to alter the genes of future generations as part of a reappraisal of the blanket ban on altering the genetic structure of embryos.

The public consultation document published by the Department of Health also raises the possibility of allowing research on human embryos such as the creation of animal-human "chimeric" embryos.

Ministers also want the public to submit its views on whether couples should be able to use embryo-screening or sperm-sorting techniques to choose the sex of their unborn babies.

Although the document emphasises that it is not the Government's intention to rewrite the existing fertility laws wholesale, the aim is to allow the law to keep pace with a fast-moving field of medical science.

Caroline Flint, the public health minister, said that the 1990 Fertility Act governing in-vitro fertilisation (IVF) technology was a landmark piece of legislation but, in the past 15 years, the science had changed along with public attitudes.

"The Act has done a good job in taking public confidence with it but we need to take stock. We need to strike the right balance," Ms Flint said. "We never expected that the Act would remain forever unchanged in the face of major developments in science and medicine," she said.

The existing law bans the alteration of the genetic structure of any cell that is part of a human embryo but the Government wants to test public opinion to see whether it could be allowed for research purposes.

It also points out it may soon be possible to repair genetic defects in embryos, sperm or eggs by genetic modification and, if that can be done safely, then it could lead to the curing of genetic disorders in subsequent generations of a family.

While the consultation document emphasises that is not yet possible, and the existing ban should be retained, it suggests future legislation might be framed so any ban could be relaxed.

"We invite views as to whether the legislation should include a power for Parliament to relax this ban through regulations (rather than primary legislation) if assured of safety and efficacy," it says.

Some fertility centres already screen IVF embryos for serious genetic disorders using a technique called pre-implantation genetic diagnosis (PGD), so only those embryos shown to be free of certain condition are implanted into the womb.

However, the advent of PGD allows embryos to be screened for other purposes, perhaps for even for ensuring that a genetic defect is deliberately screened in rather than screened out. So a deaf couple for instance could, in theory, select to have a deaf child.

The Government is asking whether selecting for certain defects - which is banned - should be allowed. Embryos could also be screened for gender, allowing couples to select the sex of their baby to "balance" a family of all boys or all girls.

"The Government seeks views on sex selection for non-medical reasons. In particular, should this be banned? Or should people be allowed to use sex selection techniques for family balancing purposes?" the consultation document says.

"If so, how many children of one gender should a couple already have before being allowed to use sex selection techniques to try for a child of the other gender?" it asks. Under the existing law, no fertility centre in Britain can offer IVF treatment to a couple unless it takes into account the welfare of the child born as a result of the treatment, including the need for a father.

The consultation document asks whether it is still valid for the state to intervene in such a way.

"Some have argued that, as the law does not intervene in the reproductive choices of people who are able to conceive naturally, it is therefore discriminatory to intervene where people happen to have fertility problems," the document says.

Lord Winston, the fertility expert dismissed the public consultation as a flawed process yesterday.

"I welcome the reopening of the debate on sex selection but the Government ought to be highly embarrassed about gauging public opinion through website consultations when their own research shows this is a deeply flawed process," Lord Winston said.

People who want to respond to the consultation have until 25 November. They can respond by e-mail to or to Christopher Cox, Department of Health, Room 651c, Skipton House, 80 London Road, London SE1 6LH

5 key issues that will come under scrutiny

Selection of child's sex

Existing fertility law prohibits the selection of an IVF embryo's gender unless it is for medical reasons, for instance to avoid the birth of a boy with haemophilia. A public consultation three years ago found there was strong opposition to sex selection for non-medical reasons but the Government would like to revisit the issue and has asked whether it should be allowed.

Altering embryo genes

There is an absolute ban on altering the genetic structure of any cell while it is still part of a human embryo - which is defined as an egg that has been fertilised by a sperm. The Government is asking whether research should be permitted to allow genetic modification for research in order to see whether it is possible to safely prevent the transmission of harmful genes, or even repair gene defects.

The role of the father

The 1990 Act specifically states that the welfare of the IVF child should be taken into account and that this should include "the need of the child for a father". Some argue this is inappropriate - there is no mention in the Act for instance of the need for a mother. The Government is asking whether the state should continue to demand this or whether references to fathers should be dropped completely.

Sperm on the internet

Sperm and eggs donated through a fertility clinic are currently controlled by existing legislation but sperm sold over the Internet falls outside the current scope of the law. The Government argues that there are concerns about the health of such sperm and the legal status of the donors. The Government wants to bring internet sperm services under the law, either by banning them altogether or regulating them.

Artificial gametes

Scientists are working on the possibility of creating gametes - sperm and egg cells - from other "somatic" cells of the body, such as skin tissue. This would be of benefit to infertile men and women. But it also raises the possibility of two women (or men) producing both sperm and eggs to produce their own biological child. The Government wants to ban the use of artificial gametes.