Women who go through early menopause and cannot have children have been offered new hope after scientists found a way of apparently getting ovaries working again.

The study could pave the way for women to one day have their own babies even though they have gone through the menopause at an early age.

Premature ovarian failure affects 1% of women under the age of 40, with one in 1,000 (0.1%) going through it under the age of 30.

The normal age for menopause is the subject of debate but experts consider early menopause to be before the age of 45.

Possible reasons include chromosome abnormalities, such as a women with Down's syndrome; enzyme deficiencies, where enzymes damage eggs and prevent the production of the hormone oestrogen; and auto-immune diseases, where the body effectively turns on itself.

Scientists at the World Congress of Fertility and Sterility in Munich said their latest work in rats could offer hope for the future.

A team from Cairo University in Egypt used stem cells to restore ovarian function in a group of 60 female rats.

The rats were divided into four groups during the experiment, with the first not given any treatment and acting as a control.

Rats in all the other groups were treated with a chemical to stop their ovaries working, with those in the second group then given injections containing stem cells.

Group three was injected with a saline solution to act as a control, and the group four rats had ovarian failure but received no treatment, also enabling them to act as a control.