Social egg freezing: trouble ahead?

By Jim Catt, Director of Embryology, Monash IVF, Victoria, Australia

Progress Educational Trust

09 February 2009

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[BioNews, London]

With the gradual and continual improvement of cryopreservation techniques comes an increased demand for these services. An example of this would be the increased reliance on the cryopreservation of embryos to support elective single embryo transfer (eSET) programmes. There is a more controversial side to these improvements, however: perhaps the most controversial being social oocyte cryopreservation, i.e. electing to freeze your oocytes for non-medical reasons.

There are a number of reasons why people would want to (or need to) freeze their eggs. The most common until recently was legislative, ethical or medical reasons. Some couples have ethical or moral objections to freezing embryos but not for oocytes. In Italy, for example, there are legal restrictions on the number of oocytes that can be inseminated and so a need has arisen for freezing supernumerary oocytes. Most Italian groups now have effective cryopreservation programmes.

Medical reasons for oocyte freezing include the inability to have a suitable sperm sample on the day of collection. This could be an inability to produce a sample or a complete failure to find sperm in a testicular biopsy. Usually these couples would have donor sperm back-up, but the may elect not to use donor material or have not signed a consent for donor use before the procedure. Here the oocytes can be frozen until the sperm issue is resolved.

Another possible reason for oocyte freezing would be where the ovaries are likely to be damaged as a result of medical treatment such as radio- or chemotherapy. This method is used only rarely as the patient has to undergo at least one round of stimulation to recover mature oocytes and their medical condition precludes this.

Social egg freezing generally arises because a woman chooses to delay bearing children. This could be because they wish to further their career before parenthood or have not found a partner with whom they wish to share parenthood. There is a second category of 'social' egg freezing: the donation of oocytes for paying customers. Failure to produce a pregnancy in these cycles has no impact on the donor since their transaction is purely financial.

Since there are a number of institutions offering social egg freezing around the world it is opportune to have a critical assessment of the technology and some of the concerns that emerge from social egg freezing.

A common perception is that oocyte freezing is inefficient and that the number of fetal heart pregnancies per oocyte is relatively low. Recent evaluation however shows that the benchmark of fetal hearts per thawed oocyte is very similar to the fresh benchmark of fetal hearts per oocyte recovered. Both of these figures are between five and ten per cent per oocyte. Modelling suggests that on average 2-3 cycles are required to give a maximum chance of a pregnancy for both types of cycle. The implication from this is that, for cryopreserved oocytes, at least 20 oocytes would give the best chances of a pregnancy. This could be deemed a reasonable chance for a medical freeze but for a social freeze the answer may be different.

Cryopreservation for social and not medical reasons means that the freezing institution is dealing with a customer and not an infertile patient. The management of customer expectations is radically different from infertile patients as there is nothing 'wrong' with them; they are simply using a service. Oocyte cryopreservation is often sold under a banner of 'future insurance'. Wording of consent forms and information sheets has to be precise and absolutely explicit about chances of success. Even so, with the best forms in the world the possibility of litigation by customers who do not achieve a pregnancy is a distinct possibility.

These customers would have invested several tens of thousands of dollars and a minimum of one stimulated cycle into their freezing and will be seriously aggrieved if their expectations are not met. In addition to meeting expectations and protecting oneself with contracts, consents etc, technology changes and as techniques improve so will results. What of oocytes frozen 10 years ago by a suboptimal method meaning that a customer does not get their desired outcome?

The potential here for 'trouble' is manifold and should be seriously considered before an institution engages in social egg freezing. I suspect that eggs frozen for social reasons will seldom be used or be used as a last resort by their owner. Since a pregnancy cannot be guaranteed then people will always try with their own fresh gametes before utilising their last chance. This might be the saving grace for the freezing institution in that they will not have to pick up the pieces after not achieving a pregnancy.