Women's egg freezing gets boost

Egg freezing looks increasingly promising as an insurance policy for women who need or want to delay having children, according to the first systematic monitoring of success rates for IVF using eggs that were frozen then thawed out.

The results come from the first year of the Human Oocyte Preservation Experience (HOPE) Registry, which is analysing the results of thawed-egg IVF over five years. "This is the first registry to collect results in a standardised way, rather than sporadic reports of single cases," says Zsolt Peter Nagy of Reproductive Biology Associates in Atlanta, Georgia.

Of the 115 IVF cycles recorded in the registry, about 90 per cent of thawed eggs survived the freezing process. With the most successful version of the technique - where eggs are frozen very rapidly - 65 per cent of women became pregnant.

This pregnancy rate is similar to that achieved when IVF eggs have not been frozen. Nagy admits, however, that "careful selection" of the patients and egg donors may have boosted the success rate. None of the eggs was frozen for more than two...