Ovary banking future looking rosy

North American scientists have, for the first time, successfully frozen, thawed and transplanted whole rat ovaries. The success, reported in a letter to Nature, could mean that women undergoing chemotherapy treatment, which usually renders them sterile, can have their fertility restored after treatment.The team, based at two hospitals in Montreal, Canada, transplanted fresh ovaries from eight rats into rats who had had their ovaries removed. Normal ovarian function was restored in all of these animals. In addition, seven ovaries were frozen, thawed and transplanted to recipients. Four rats had some ovarian function restored and one was pregnant with two healthy fetuses.

The success has led scientists working in the area to think that whole ovary freezing - rather than strips of ovarian tissue - might be the best method of restoring ovarian function in humans. Patients who initially responded well to transplants of strips of ovarian tissue, did not go on to get pregnant. By comparison, whole ovaries frozen using newer and gentler methods, seem to be better able to restore function, although the technique has not yet been attempted in humans.

Professor Roger Gosden, who led the Canadian research before moving to the Jones Institute for Reproductive Medicine in Virginia, US, expects the whole ovary freezing technique to be available to human patients in two to three years. 'All the gynaecology surgeons I've spoken to say it should be straightforward to do an ovarian transplant. There won't be problems with surgery.'