Young women could end up childless if they postponed motherhood in the hope that fertility treatment would help them conceive, nurses warned yesterday.

Nurses experienced in fertility problems said there was a growing belief that women could put off pregnancy by freezing eggs in their 20s or early 30s. But the reality was that the chances of having a live baby from frozen eggs was extremely low, with fewer than 50 babies born worldwide.

The warning was issued at the Royal College of Nursing's annual conference in Harrogate in an attempt to persuade more women to have babies earlier in life. There is a growing trend for women to delay childbirth until they reach their mid-30s or even their 40s to pursue their careers.

But Debbie Barber, the chairwoman of the college's fertility nurses group, said women were reducing their chances of giving birth because they did not understand their declining fertility or the scope of reproductive technology. "Media coverage and public debate may encourage a simplistic view that a woman may defer having children when she is younger but just pop a few embryos in the freezer in case she wants to use them later. There is great concern about using these techniques for social reasons and the commodification of children." Pro-life groups had also warned against "putting babies on ice".

The college said human sperm had been frozen, stored and used for artificial insemination for many years. The use of frozen embryos had been an important advance for infertile couples and partners who had to treated for cancer. But freezing human eggs was much more difficult because they were large cells with unique features, requiring invasive treatment for retrieval and gradually deteriorated upon being frozen.

The college said: "[We] are concerned that there is a general perception that we can now control all aspects of fertility and defer having children until socially convenient. This is not so."