In Germany and Switzerland, egg donation is prohibited, but embryo donation and adoption are generally permitted due to the undefined legal situation. However, the commercial use of embryo donation (where the donor is paid) is punishable by law.

Nevertheless, more and more infertile couples or single women with an unfulfilled desire to have children are considering treatment abroad (e.g. Spain). But how does embryo donation or adoption work? Who is it suitable for and when is it appropriate? Are there any medical requirements that need to be met? What are the medical risks and legal aspects? In this article you will find the answers to all these questions and more.

What is embryo donation? What is embryo adoption?

In addition to the well known and common procedure of paying for eggs to be fertilised by donor sperm, there is also what is known as embryo donation and embryo adoption. Let's take a look at what these two terms mean.

Embryo donation becomes possible when a couple has successfully completed their fertility treatment at an IVF centre and have a surplus of eggs. In this case, the law on assisted reproduction allows the couple to decide whether to freeze the embryos for their own use, donate them or discard them.

If the couple decides to freeze them for embryo donation, they will be given detailed counselling, asked for permission to thaw these fertilised eggs at a later date, and finally asked to sign the embryo donation release form. For this purpose, a release contract is signed with the IVF centre, in which they officially sign as an embryo donor couple.

On the other hand, embryo adoption means that a suitable couple or single woman uses the donated embryo for a previously impossible pregnancy. Embryo adoption can take place if an infertile woman or couple applies for it and, following a successful medical examination, the woman meets all the medical requirements and, in the opinion of the doctors, is able to carry a pregnancy to term despite her infertility. Embryo donation and adoption are completely anonymous. The thawed, fertilised egg is then transferred to the recipient's uterus at an appropriate time in her cycle. If the baby is born, the recipient, who gave birth to the child herself, is also considered the 'biological mother'; the embryo donor couple, on the other hand, are considered the 'genetic parents'.

Who is embryo adoption suitable for?

Embryo adoption is suitable for:

• Women of legal age who are mentally and physically healthy.
• Women who do not have their own eggs or who have not had ovaries since birth.
• Women who do not become pregnant despite in vitro treatments.
• Carriers of genetic diseases who do not wish to have affected children
• Couples / women who are on the waiting list to adopt a child
• Single women or women with a same-sex partner
• Couples with fertility problems and multiple failed fertility treatments and/or in vitro fertilisations
• Women who have had multiple miscarriages

Medical requirements for embryo donor and recipient couples

IVF centres screen both the donor couple and the future recipient. Only embryos from healthy female patients under the age of 37 who have just successfully undergone in vitro fertilisation can be donated. There is no age limit for male sperm donors. Both have undergone preliminary medical examinations (STDs - HIV, syphilis, hepatitis, BWR, CMV, chlamydia, etc.).

Adult women under the age of 45-49 (the age limit depends on the IVF centre) and their partners are eligible to receive donated embryos if they are physically and mentally healthy. However, if they are infertile, the specialist in charge will be able to assess whether they can carry a pregnancy to term on the basis of their physiology and lifestyle.

Embryo donation process

If a couple with fertility problems decides to undergo IVF using their own eggs and sperm, the specialist will begin a series of tests that will take about two weeks.

When menstruation begins, the ovaries are scanned to make sure they are not active and that the lining of the uterus is not too thin. The patient is also given follicle stimulating hormone (FSH) to inject under the skin every day for 9-12 days to ensure follicle production. This phase is also monitored by 2 or 3 ultrasound scans to check the effect of the hormone injections and the growth of the follicles. When the specialist considers that the follicle size is sufficient, the patient is injected with human chorionic gonadotropin (HCG) to release the eggs into the follicular fluid and induce ovulation. About 36 hours after the injection, a needle is inserted into the patient's vaginal wall under general anaesthetic (under ultrasound control) and the eggs are retrieved. These are fertilised with the partner's sperm in vitro, cultivated and cell division is closely monitored for 5 days. After this, 1 to a maximum of 3 good quality embryos are transferred to the patient's uterus through the cervix using a catheter, and oestrogen and progesterone therapy is continued. The couple can then decide what to do with the remaining successfully fertilised eggs:

• The donor's own (genetic) embryos are used at a later date if she wishes to have children again.
• be donated to other recipients with an unfulfilled desire for a child.
• be destroyed.
• be donated for research purposes.

After two weeks, a pregnancy test is done and, if the result is positive, the patient takes hormones until the end of the first trimester. A further two weeks after a positive test, an ultrasound scan is done to confirm the pregnancy. As with normal pregnancies, there is a risk of miscarriage, complications or foetal malformations until the end of the first trimester, even after in vitro fertilisation and implantation of the embryo.

If the couple choose to donate embryos, the fertilised eggs will be frozen and carefully stored by the IVF clinic for future embryo adoption.

Embryo adoption procedure

There are different waiting lists for embryo adoption depending on the country, and no official adoption formalities are required as with child adoption. The adoptive parents or the mother of the embryo only have to sign the information and consent form.

At the first visit, preliminary gynaecological examinations are carried out to assess the woman's health and whether she is able to carry a pregnancy to term. If this is confirmed, treatment can begin. This involves an ultrasound scan and a painless probe test, which is used to transfer the thawed embryos to the uterus. When allocating the donated embryos, the IVF clinic will generally try to match the recipient's appearance by selecting embryos from donor couples with similar hair and eye colour, skin type, weight, height and blood group.

To prepare the endometrium, either oestrogen tablets or patches and progesterone vaginal suppositories are prescribed to match the patient's menstrual cycle. In addition, an ultrasound scan is performed between the 10th and 12th day of the cycle to check the build-up of the endometrium.

An appointment can then be made with the couple or the woman for the embryo transfer, ideally 2-4 weeks after the first visit.

Embryo transfer is an outpatient procedure, so no hospital stay is required. After the transfer, the patient must lie down in the clinic for 30-45 minutes before going home and should avoid physical exertion for the first few hours after the transfer. A pregnancy test is carried out two weeks after the transfer. If it is positive, treatment with suppositories and patches will continue for another two months. Subsequent pregnancy tests will be carried out by your gynaecologist of choice.

Depending on the IVF centre, the chances of a successful embryo transfer are around 57-63% or more.

Medical risks

The medical risks of embryo donation lie with the donor herself. In particular, there are risks of anaesthesia, tissue damage and thrombosis, which can occur during egg collection under general anaesthesia. In addition, the hormonal stimulation caused by the obligatory hormone treatment can place such a physical and psychological strain on the embryo donor and recipient that it can lead to overstimulation syndrome (see OHSS).

Legal aspects

After carrying the donated embryo to term, the recipient is legally considered to be the biological mother and her husband the legal father. The embryo donor and the recipient are legally considered to be the genetic parents.

Both embryo donors and embryo recipients should consider in advance whether they want to give the future child the right to information so that it can find out where it comes from. This is very important because the donor's children are full siblings of the donated embryo and will grow up in different families. However, in some countries (e.g. Germany), the donor couple's details remain anonymous by law, so the conceived children have no chance of finding out about their genetic parents.