London, 9 July 2013: Egg freezing as insurance against age-related infertility is a growing trend inmany countries. Women who bank oocytes for use at some time in the future hope to buy alittle time in their search for a suitable partner.
However, a study from one of Europe's largest centres in reproductive medicine suggests thatmany of those banking eggs believe they will never use them - even though they still recognisethe experience as "positive". The majority of those who did (and did not) freeze their eggswished they had done so at an earlier age.
The study of what is an increasingly common procedure was performed at the hospital of theFree University of Brussels, Belgium, and was presented at the annual meeting of ESHRE by DrDominic Stoop from the hospital's Centre for Reproductive Medicine.
This was a study of what the investigators called "oocyte banking for anticipated gameteexhaustion", a term which reflects the motivation of participants and the biological certainty(the depletion of ovarian follicles over time) which the procedure hopes to overcome.
The study was a follow-up survey of 140 women considering egg banking between 2009 and2011. Their mean age was 37 years. They were surveyed with a questionnaire on their relationaland reproductive circumstances, their attitude towards oocyte banking and their futurereproductive plans. Of those surveyed, 86 women (61.4%) completed at least one treatmentcycle from which eggs were collected and cryopreserved. The non-bankers included 54 womenwho either preferred no treatment (51%) or attempted stimulation but cancelled because ofpoor response (3%).
Results showed that of those banking eggs around one-third (34.1%) believed they would neverhave to use them, with many (75%) indicating at follow-up that they considered the use offrozen oocytes less likely than anticipated at the time of oocyte collection. However, nearly all(96.2%) said they would do it again - but preferably (70.6%) at a younger age. Among thoseactually banking eggs, nearly all said they would recommend the treatment to others.
The survey also showed that those banking eggs accepted a higher age for motherhood thanthose not doing so (43.8 years and 42,5 years) and all were still keen to have a baby. However,in terms of relationships and reproductive potential, there appeared little difference betweenthe egg bankers and non-bankers, with similar steady relationships (around 50%), attempts atconception (around 35%) and experience of infertility (7%).
The investigators thus suggest that oocyte freezing to preserve fertility provides importantpsychological reassurance for those opting to use the technology, as expressed by the positiveresponse of all participants, even those with a lower intention of ever using their eggs.
"Our results indicate that most women who have had oocyte cryopreservation have no regretsabout it, but do wish they had done so at a younger age," said Dr Stoop. "This makes sense,because the younger the eggs, the better the chance of pregnancy. But ideally oocytes arecryopreserved in the early thirties, when oocyte quality is still good and we can retrieve a goodnumber of oocytes per cycle. While oocyte quality and quantity are better at a younger age,women in their twenties still have a relatively long fertile period ahead of them, with a greatchance that they may never need the cryopreserved oocytes."
Dr Stoop added that, while oocyte cryopreservation has become a mainstream fertilitytechnique with excellent results, especially in oocyte donation programmes, the clinicaloutcome of oocyte cryopreservation for anticipated gamete exhaustion at a more advancedmaternal age is less certain. "Although the pioneer group in our study appears to be satisfied,"he said, "a more efficient preservation of fertility would have required oocyte freezing at asignificant younger age."
Since 2009, about 140 women have had a minimum of one oocyte cryopreservation cycle at theCentre for Reproductive Medicine in Brussels. A total number of 2380 oocytes have beencryopreserved, with an average of 17 oocytes per woman (from an average of two cycles each).So far, only one woman has come back to thaw her oocytes (which were cryopreserved at theage of 39), but the embryo transfer did not result in pregnancy.
Source: European Society of Human Reproduction and Embryology