The jury’s out as to whether egg-freezing is a boon or a hidden threat to human fertility. Gafencu’s Hira Desai investigates…
Cryopreservation – the practice of freezing living organisms and then restoring them to life at a later date – has long been associated with the more Frankenstein-like branches of science.
Of late, though, the practice has been somewhat rehabilitated. Ever since 2012 – when the American College of Obstetricians and Gynecologists (ACOG) deemed that the process had passed the merely experimental stage – oocyte cryopreservation has allowed women across the world to freeze their eggs as insurance against future infertility.
Given the relative infancy of the technique, however, how sure can we be that, when subsequently defrosted, these eggs will retain their original potency?
With any new scientific innovation, there’s always the possibility that negative ramifications could take years or, even, generations to fully manifest. Thankfully, though, for the moment at least, all the research relating to oocyte cryopreservation indicates a positive outcome.
This should come as some relief to many of the businesses, such as Apple, Google and Facebook, that have positioned themselves firmly at the ‘right on’ end of the employment spectrum, chummily – and not at all creepily – offering female staff the chance to freeze their eggs for free.
Overall, medical opinion – while couched in suitably cautious terms – seems broadly supportive of the technique. Endorsing it, while still leaving herself a little wriggle room, Dr Kate Devine, an infertility specialist and a co-director of Washington-headquartered Shady Grove Fertility, says: “The data we have is quite reassuring with regard to the babies produced from frozen eggs. In particular, it’s a huge benefit to those women who, otherwise, might not able to have a child from their own eggs.”
Although usually touted as an entirely new technique, egg-freezing has much in common with a number of earlier infertility treatments, particularly in-vitro fertilization (IVF). As with IVF, oocyte cryopreservation involves a woman’s ovaries being hormonally stimulated prior to eggs being harvested. The extracted eggs are then preserved in specialised capsules – either through a slow-freeze or a flash-freeze process – and stored in a cryopreservation facility.
At a later date, they are then thawed and fertilized, again using a similar process to IVF. Once this step has been completed, they are re-inserted into the would-be mother’s womb. In another echo of IVF, even at this stage, success is far from guaranteed.
Despite the enthusiasm of its advocates, it’s around this point that a positive outcome becomes more an article of faith than the subject of exhaustive scientific research. As the process was only formally approved for widespread use six years ago, there is still comparatively little data from which definitive conclusions can be drawn. It is this lack of quantifiable data that has made some medical professionals wary of recommending the process to all but those with a clear medical requirement. Typically, those that are steered in its direction are women faced with the risk of sterility from looming cancer treatments or those who may have to contend with similarly fertility-compromising surgical procedures.
As far as ethical guidelines go, the most strident to date was issued in 2013 by the American Society for Reproductive Medicine (ASRM) – an organisation representing approximately US 500 fertility clinics – which, together with SART, concluded: “There is not yet enough data to recommend oocyte cryopreservation for the sole purpose of circumventing reproductive aging in healthy women.”
To be fair, though, most of the concerns that do exist relate less to the efficacy of the technique and more to general issues regarding pregnancy among older women. The thinking here is that the wider adoption of egg-freezing as a way of postponing pregnancy in the general population would, undoubtedly, result in a surfeit of mothers in their 40s, 50s or even later. The oldest patient to successfully undergo IVF treatment, it should be remembered, was an Indian woman in her early 70s.
While the benefits of egg-freezing are, as yet, still languishing in the unproven file, there is a clear medical consensus as to the risks represented by pregnancy among post-35-year-olds.
A number of studies indicate a greater propensity for giving birth to a Down Syndrome child in the case of older mothers. Among those aged 25 or below who carry a child to full term, the number of Down Syndrome births is approximately one in 1,250. For mothers aged 40 or above, however, this rises to one in 100, a massive increase in statistical terms.
On the positive side, there is also the case of Emma Gibson. Although, technically, she won’t have her first birthday until November 25 this year, she was actually “conceived” in 1992.
Despite the surely record-breaking quarter century interlude between her conception and her delivery, young Emma seems none the worse for her experience. Indeed, her father has gone on record as saying: “She’s pretty much perfect given she spent all those years deep-frozen.”
Emma may well prove the biggest thumbs-up oocyte cryopreservation could ever have hoped for.
The full version of this feature appears on Gafencu Magazine’s April 2018 print issue as ” Ova Kill” by Hira Desai. You can download the free app for digital editions of the magazine.