The Law 3305/2005 is the one dictating how one should proceed when it comes to dealing with fertility treatments in Greece.
This policy establishes, in addition to a number of aspects, the boundaries regarding the maximum number of embryos a woman can have transferred. Such limit is determined by two main aspects:
- The age of the patient
- Where the ova come from, i.e. whether they are donor eggs or own eggs
Using donor eggs or own eggs?
Egg donors are young women who enjoy good health. This is precisely the reason why their oocytes are expected to be of high quality, which in turn may increase the chances of obtaining better embryos—with high embryo implantation potential.
On the other hand, when own eggs are used, their quality will be poorer in general terms. The reason behind this is that patients are usually older than donors, and also because a woman’s egg quality and supply keep on diminishing over time.
- A maximum of two embryos in women aged 39 or less who are about to use their own eggs. Women aged 36 to 39 should have up to three embryos transferred from the 3rd cycle onwards.
- In the case of 40-year-old women using own eggs, up to three embryos can be transferred. This is due to the fact that egg quality is poorer at this age, and therefore embryo implantation chances are lower. Transferring a higher number of embryos implies increasing the likelihood that at least one of them attaches, therefore achieving reproductive success.
- In women aged 40 or more, up to four embryos can be transferred provided that they have been created from her own oocytes. There is a weak probability that this leads to a multiple pregnancy, taking into account the fact that egg quality is lower at this age.
- Regardless of how old the recipient is, whenever donor eggs are used, the maximum number of embryos allowed by the Greek law is limited to two.
Deciding on the number of embryos to transfer
The reason why the number of embryos to transfer is limited is because we always aim to reduce the chances of having a multiple pregnancy. This type of pregnancy may involve a greater number of risks not only for the mother, but also for the fetuses if compared to a singleton pregnancy.
The main goal of assisted reproductive technology is to achieve a full-term pregnancy, and therefore the birth of a healthy child. This is the reason why sometimes the recommendation is to transfer multiple embryos, thereby increasing the chances of embryo implantation and pregnancy.
Keeping in mind both aspects, the intended mother will have to decide, in accordance with the law and following recommendations given by a physician, the number of embryos she wants to have transferred. Other factors requiring consideration are: uterine receptivity, number of embryos available, conditions of laboratories dealing with cryopreservation of embryos, etc.
Should multiple embryos be transferred, we would increase the likelihood of multiple births, but on the other hand chances of success will be higher, too. It will be necessary to determine the balance between the benefits and harms, and make an informed decision based on the conclusions drawn from that assessment.