After transfer there are usually excess embryos that can be frozen for later use. Only embryos that are of good quality are suitable for freezing. Embryo freezing does not harm the embryo. There are over 500 000 babies worldwide that were born after the transfer of frozen-thawed embryos.

American Hospital of Istanbul has a very successful embryo freezing program. Our pregnancy rates for frozen-thawed embryo transfers are approximately equal to fresh transfers. A couple can elect to have their frozen embryos replaced after an unsuccessful attempt or after delivering a baby. Preparation for frozen embryo transfer is a relatively simple procedure that entails stimulation of the inner lining of the uterus with orally used medications.

Besides conventional slow freezing we have recently initiated a newer freezing method called vitrification. Vitrification is associated with higher embryo survival after thawing and better pregnancy rates.