Embryo Donation

An embryo is the product of the fertilisation of an oocyte (female gamete) by a spermatozoon (male gamete). It is a new entity made up of a group of cells that will give birth to a human being, if it can be implanted in the uterus and a healthy pregnancy continues.

This is a treatment in which embryos donated by another woman or couple are transferred to a recipient or couple. The donated embryos come from people who have already undergone medically assisted reproduction treatment and have surplus vitrified embryos. In accordance with current legislation, these embryos can be donated to other women or couples, giving them the opportunity to have a child.

With gamete donation, the donated gamete must also be fertilised to produce embryos, which can then be transferred to the recipient’s uterus. With embryo donation, the embryos are already formed and cryopreserved, and are immediately transferred to the recipient’s uterus after thawing.

Embryos can only be donated with the express consent of those with rights to them. These embryos invariably result from MAP treatments, during which viable surplus embryos are obtained which, due to a legal obligation, must be cryopreserved.

At CETI, embryo donation is recommended in cases of:

• Poor quality of a couple’s oocytes and spermatozoa, resulting in embryos that are unable to implant.
• Lack of a male partner. Women without a male partner and with low ovarian reserves, ovarian insufficiency or menopause, resulting in poor quality oocytes.
• Repeated failure of medically assisted reproduction techniques using own gametes.
• Genetic diseases. When there is a genetic or hereditary disease that prevents the use of one’s own gametes, associated with ovarian insufficiency or a serious male factor.

Embryo cryopreservation is a complementary technique to IVF (in vitro fertilisation). In recent years, advances in cryopreservation methods, particularly the development of the vitrification protocol, have meant that damage to cryopreserved cells is irrelevant. This technique enables embryos to be stored appropriately, whether for the short or long term.

Endometrial preparation: This is a treatment with oestrogens that is started as soon as menstruation, to prepare the endometrium to receive the embryos. This treatment phase generally lasts around 12 to 14 days, and requires ultrasound monitoring of the characteristics of the endometrium.

When the endometrium reaches a sufficient thickness, a second hormonal treatment (progesterone) is started so that the embryo can be transferred in the following days.
Thawing of embryos: embryologists determine which embryos will be thawed during the transfer.

Donated embryo transfer: This is a generally painless process that involves depositing the embryo(s) in the uterus using a very fine catheter passing through the cervix. The law limits the maximum number of embryos that can be transferred to two.

As with oocytes and sperm, donors must remain anonymous to the recipient couple and vice versa. The lifting of anonymity does not only apply to the person born as a result of this process, if they are aware of it and when they reach the age of majority.

Law no. 58/2017 of 25 July – Article 10 – Donation of sperm, oocytes and embryos.

1 – Oocytes, sperm or embryos donated by third parties may be used when, in the light of objectively available medical-scientific knowledge, pregnancy or pregnancy without serious genetic disease cannot be achieved by the use of any technique using the recipients’ gametes and provided that effective conditions are ensured to guarantee the quality of the gametes.
2 – Donors may not be considered as the parents of the unborn child.