Egg freezing does work to create babies, however only a small number of women have been through this procedure worldwide. At the moment it is difficult to give reliable success rates. Generally, the younger a woman is at egg freezing, the better her chance of a pregnancy from the eggs will be. If good quality eggs are frozen an average of 75% will survive the thawing process. Fertilisation then occurs in 60-70% of these thawed eggs. This means that it is best to freeze ten or more eggs in one treatment cycle to have a reasonable chance of a pregnancy in the future. Worldwide, data at present shows that babies born from frozen eggs have no increase in abnormalities or birth defects.