Cryopreservation of embryos

Freezing of embryos is a method thanks to which we are able to preserve surplus quality embryos for as long time as needed. They are kept in liquidized nitrogen and ready for later transfer. Cryopreservation in used when there is enough of quality embryos which have not been transferred in given cycle ( for example for the risk of multiple pregnancy). In case of serious Ovarian hyper-stimulation syndrome or not suitable conditions for transfer ( other illness of the patient, low lining etc.) all of the embryos are frozen. Despite of standardization of the procedure not all of the embryos will survive the defrosting in a condition suitable for transfer.

The success rate of the transfer of frozen embryos- defrosted embryos ( cryo-embryo transfer) is lower than with fresh embryos. For the lady this is more convenient as she does not need to repeated hormonal therapy and egg retrieval. Based on current knowledge there is not know increased risk of abnormalities or congenital developmental defects caused by this method.