Oocyte cryopreservation or egg freezing allows women to postpone motherhood
Women of reproductive age who acquire a form of cancer necessitating chemotherapy may choose to freeze eggs. Many of the chemotherapeutic drugs may result in loss of fertility due to the toxic effects they have on eggs. These women may choose to freeze eggs before starting chemotherapy thus preserving their ability to get pregnant later.
Other reasons to explore egg freezing
Some women have religious, ethical or moral beliefs regarding the storage of embryos which prevent them from doing IVF. For these women, not all their eggs need to undergo fertilization at the same time. We can freeze the extra eggs.
Occasionally, during an IVF cycle a situation arises where sperm may not be available on the day of fertilization. This might occur if the man is unable to produce a specimen due to anxiety or illness. We can then freeze the eggs and use them later when the sperm becomes available.
Looking at donor eggs and oocyte cryopreservation
The use of egg freezing may be useful for obtaining and storing eggs from egg donors. At present, most egg donation cycles involve the simultaneous stimulation of the egg donor and preparation of the recipient’s uterus. This may be inconvenient for one or the other of these women or sometimes the eggs are ready to be retrieved before the recipient’s uterus is ready to receive them. If the eggs from potential donors are obtained and frozen in advance, a donor egg bank could be created which would make the process more convenient.
We have recently completed a study in our laboratory comparing the two different freezing methods that are currently available. We used eggs obtained from egg donors and demonstrated as others have, that one method (MicroSecure Vitrification) was far superior to the other method (Slow freezing). Using vitrification in this study we had an egg survival rate of 90% after thawing with subsequent 81% rate of fertilization. We transferred an average of just over 2 embryos per patient and obtained an implantation rate of 39% and a live birth rate of 47%. All the babies were born healthy and had normal child development checkups at their 1 year exams. Since then, the technology has been offered to patients with similar success.
Therefore we feel that egg freezing is a technology whose time has finally come and we are happy to offer this procedure to our patients when appropriate. Contact us to learn more.