The fertility watchdog, the Human Fertilisation and Embryology Authority, is to review egg giving - the practice by which a woman will donate all her eggs from the first cycle of fertility treatment (when she is stimulated with powerful drugs to superovulate) to a recipient who cannot produce eggs of her own. In some clinics the donor is then offered cut-price treatment on the second cycle of fertility treatment.

Suzi Leather, chairwoman of the authority, said: "It is important that with any form of egg donation the women involved are given all the information needed to make informed decisions about their treatment and this includes details of any risks involved."

Fertility specialists such as Lord Winston have criticised egg giving, saying it puts pressure on poorer women to go through two cycles of treatment when one cycle may be enough to help them to conceive. "I do not think it is desirable. I think it's ethically unsound. It is exploiting people who are desperate," Lord Winston said.

The authority said the outcome of its review on egg giving would be completed and made public by the end of the year. A spokeswoman said it was part of a wider review of egg donation, which also includes the practice of egg sharing, when half of one cycle of eggs are given to a recipient and the rest kept by the donor.