Oocytes can be frozen for non-medical reasons (‘social freezing’) if a woman wishes to postpone pregnancy and save her high-quality oocytes for a possible future desire to have children.
The most important reason to choose for the cryopreservation of oocytes is the decrease in oocyte quantity and quality that comes with age. Social freezing is a possibility if there is no short-term desire to have children but the woman in question is looking for certainty in her fertility in the future.
Since the chances of pregnancy start to decrease notably at the age of 35, social freezing has a higher success rate when women start to consider it as early as possible. At least ten, but ideally closer to fifteen or twenty, oocytes should be available for cryopreservation in order to have a real chance at a pregnancy in the future. This means that more than one treatment may be necessary to achieve this number.
Even if the circumstances are ideal, there is no guarantee that social freezing will result in a pregnancy. The cost of non-medically indicated freezing of oocytes is not (yet) covered by insurance in the Netherlands. This means that, with the exception of the intake consultation and preparations, the treatment itself will be charged to you directly.
The number of available oocytes a woman has is already determined at birth, since she will not grow new oocytes in her lifetime. So as the years go by, her reserve of oocytes shrinks slowly.
This may cause two problems when trying to fulfil a desire to have children later in life:
The older a woman is, the fewer oocytes she has available for ovulation. This lowers the odds of fertilization.
Her age also has an influence on the quality of the oocytes. Starting at roughly the age of 35, the chances of the child having congenital defects, complications occurring during pregnancy and miscarriages all increase as the chances of conceiving at all continually decrease. This development actually starts even before a woman’s 35th year, but the influence is almost negligible then.
Social freezing can increase a woman’s chances of conceiving and sustaining a pregnancy at a later age by taking healthy oocytes as soon as possible and keeping them safe in storage.
If someone chooses to freeze their eggs, the first step is to obtain as many oocytes as possible. To this end, a hormone treatment is used to stimulate oocyte maturation. We use regular ultrasounds to monitor the follicles’ (small sacs containing the oocytes) maturation process. When the time is right, the mature oocytes are sucked out of the ovaries using a thin, hollow needle.
There is no need for the woman to worry about having a diminished ovarian reserve after this, even though several oocytes are taken away in one go, because only a certain number of oocytes are receptive to stimulation every month. In a natural menstrual cycle, only a single follicle ovulates; the rest of that month’s oocytes is lost. During hormonal stimulation, those other oocytes are used too, instead of just the one.
The oocytes are frozen at -196°C and can be safely stored for years. The more oocytes are stored, the higher the odds are of a successful pregnancy at a later date. Recent scientific research shows that the chances of having a living child are 40% when 10 oocytes were stored, 60% when 12 oocytes were stored and 90% when 20 oocytes were stored, provided these oocytes were obtained during the mother’s most fertile period (before the age of 30).
If a couple desires to have children and are unable to do so the traditional way, they can instead use cryogenically preserved oocytes. These will be fertilized using the partner’s sperm (or that of a sperm donor) outside the mother’s body, using an intra-cytoplasmic sperm injection (ICSI). After that, no more than three of the developed embryos will be transferred into the mother’s uterus.
Seeing as the odds of conceiving naturally start to lower after reaching the age of 30, it’s smart to do social freezing as early as possible. Recent scientific research shows that the chances of having a living child are 40% when 10 oocytes were stored, 60% when 12 oocytes were stored and 90% when 20 oocytes were stored, provided these oocytes were obtained during the mother’s most fertile period (before the age of 30).
Social freezing increases the odds of a pregnancy later in life, but there are no guarantees. In order to increase those odds, we’ll usually freeze and preserve multiple oocytes. The older a woman is when social freezing is done, the lower the chances are of a later pregnancy using those oocytes, because oocyte quality is already lowering. Therefore, we advise extracting as many oocytes as possible, which may be made more difficult by the fact that the patient’s ovarian reserve is already decreasing. It may be necessary to do several hormonal stimulation and oocyte retrieval procedures, depending on your situation.
Studies have shown that children developed from cryogenically preserved oocytes have similar risks as those developed from regular IVF/ICSI treatments. The hormone treatment necessary to do socialfreezing generally has no severe physical consequences. Thanks to specific protocols we implemented, ovarian hyperstimulation syndrome (OHSS) is rarely an issue. We offer personalized advice as part of your treatment.