Every in vitro fertilization (IVF) procedure involves ovarian stimulation of a woman’s menstrual cycle with the purpose of obtaining an elevated number of eggs. By doing this, we increase the chances of obtaining viable embryos, therefore increasing the odds of achieving your goal of becoming a parent.
Since a large amount of embryos is usually obtained but no more than 3 embryos can be used for the embryo transfer in accordance to Spanish Law regarding Assisted Human Reproduction Techniques (henceforth, LAHRT), the number of leftover embryos is often high. What should be done with them?
Fate of unused embryos
Good quality embryos that have not been transferred to the mother’s womb are usually cryopreserved, pending a decision from the prospective parents as regards what their fate will be. Thus, they can make up their minds out of the following possibilities:
- Own use for future fertility treatments, either because they wish to have a second child or due to failure if the first IVF cycle.
- Donation for research purposes.
- Donation for reproductive purposes, which is to say, donating the embryos for being transferred to another woman.
- Embryo destruction or withdrawal from the embryo freeze media, an action only allowed as long as the woman’s childbearing age has come to its end.
When a couple decide to donate them to other couples, the process is known as embryo donation, also known as embryo adoption, since a couples donates them and the prospective parents “adopt” them.
Adoption of supernumerary embryos
The steps followed when adopting embryos donated by other couples are simple and painless.
The only stage required for this to be done is preparation of the endometrium so that it reaches its reception-ready phase. To this end, the woman has to take hormone therapy medicines for around 14 days either through patch route or orally.
Once the endometrium has reached its adequate size—trilaminar endometrial morphologic pattern and at least 8 mm in thickness—, the embryos are thawed and transferred, pending embryo implantation and therefore pregnancy.
Embryo donation is an option available for every person or couple willing to have a baby and/or suffering from a fertility problem. However, it is especially indicated in the following cases:
- Infertile couples
- Repeated implantation failure (RIF)
- Recurrent pregnancy loss (RPL)
- Genetic disease likely to be transmitted to offspring
- Single women
- Lesbian couples
Advantages of embryo donation
Embryo donation allows for both time and complexity of the treatment to be reduced, since the steps of ovarian stimulation and egg retrieval are omitted.
Nevertheless, this procedure also involves a series of drawbacks. The main one is that the unborn child won’t carry the genetic code of the adoptive parents. This might be frustrating for some parents and, for this reason, they are recommended to seek psychological counseling in order to cope with the fact that they have no choice but to turn to embryo adoption.
Reproductive cells used for obtaining the embryos may come from the couple donating them after an IVF cycle or from donors, since the donor couple may have used donor eggs and/or sperm for their fertility treatment.
Depending on various factors—quality of the gametes from which the embryos have been created, their development, and survival ability after the freezing-thawing process—embryo adoption may be more or less successful.
Finally, embryo donation has another advantage, which is the cost of the treatment, usually way more cost-affordable than IVF using own eggs and sperm.