MOST women who freeze their eggs to preserve their fertility would consider using them to become single mothers, according to research in the United States.

A study of patients who have had their eggs frozen at an IVF clinic in New York suggests that 80 per cent would think about having them fertilised with donor sperm if they failed to find a suitable partner.

Many of the women, all of whom were childless and single, said that they had decided to keep some of their eggs on ice to “take the pressure off” their search for a man to father their children. If they never found him, their stored eggs would give them a better chance of motherhood.

The researchers found that 40 per cent of the women were definitely prepared to become single parents using their frozen eggs; another 40 per cent were still thinking about it. Only 20 per cent said that they would not consider having them fertilised without a partner.

Those who were willing to become single mothers said that they would probably thaw their eggs for fertilisation by sperm donor between the ages of 40 and 43, unless they found a suitable partner before that.

The research, from a team led by Alan Copperman, of Reproductive Medicine Associates in New York, is the first to examine the psychological motivations of women who decide to have their eggs frozen for social reasons, rather than to preserve their fertility during cancer treatment that could make them sterile. Details were presented at the American Society for Reproductive Medicine conference in New Orleans.

Although the study was small — it involved 20 women — it suggests that the first group to take up the option of egg-freezing are doing so chiefly to take their fertility into their own hands.

“A number of women said they were interested in egg-freezing to take the pressure off the search for relationships,” the researchers said. “Cryo-preservation meant the freedom to wait, and to not settle for a mate because they were in a rush to conceive.”

Although it has long been possible to freeze sperm, egg-freezing is more complicated because of the cell’s larger size and high water content. It is only just starting to become a practical option for women. The first baby conceived using a frozen egg was born in 1986, but only about 300 have been born since.

New techniques are changing this: a method called vitrification allows eggs to survive the thawing process much more reliably, and pregnancy rates using frozen eggs now approach those achieved with standard IVF.

It has been legal in Britain to fertilise thawed eggs since 2000. Two babies have already been born, and 22 clinics are licensed to offer the service.

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