By fertility experts from Spain.
The egg donation treatment has completely changed the field of reproductive medicine. It is a great way to overcome obstacles such as patients’ advanced age and the decline of eggs’ quality and quantity. As a result, pregnancy success rates with egg donation are significantly better than pregnancy rates in IVF cycles using woman’s own eggs. In fact, egg donation can raise the likelihood of achieving a successful pregnancy up to 70% in just one cycle.
But despite all those obvious advantages, the idea of using donor eggs to conceive is still considered a touchy subject and remains a taboo for some fertility patients. Many IVF specialists admit that it is generally difficult to convince a woman that the quality of her eggs is not good and the egg donation seems to be the most reasonable solution for her. And, to be honest, it is not surprising at all. Going for donor eggs is probably the toughest decision one has to make over the course of own fertility journey.
Egg donation is defined as the process in which a fertile woman donates her egg (or oocyte) for the purpose of assisted or third-party reproduction. In other words, donor’s ovaries are stimulated to produce multiple mature eggs, which are then donated to another woman (a recipient) to help her conceive. Eggs may be frozen for later use or fertilised in vitro. In case of the latter, the resulting embryos are transferred into the recipient’s uterus.
If the embryo implantation is successful, it is followed by a pregnancy that is the same as all other pregnancies, either natural or through IVF. The recipient is suggested to have all the necessary pregnancy scans and tests and is expected to remain under obstetrician’s medical care until the childbirth as well as afterwards.
The indications for donor eggs
The basic indications for egg donation are diminished ovarian reserve (DOR) and primary ovarian insufficiency (POI), also called premature ovarian failure. As women age, their natural reproductive potential starts to decrease. It is a well-known fact that women over 40 years old have reduced fertility in general, what comes from ageing of the eggs and leads to reduced pregnancy success and an increase in miscarriages.
DOR is a decrease in the quality and quantity of woman’s eggs in her ovaries, which has serious impact on her fertility. POI, on the other hand, happens when the ovaries stop functioning before the age of 40. The ovaries do not produce normal amount of the hormone estrogen or release eggs regularly, leading to their complete depletion. POI may be referred to as early menopause occurring before the age of 40 and it affects approximately 1% of the female population
DOR can be diagnosed through high levels of follicle stimulating hormone (FSH) and low levels of anti-Müllerian hormone (AMH). Women with POI have raised FSH levels and low levels of estradiol (estrogen). FSH and estradiol levels can be measured by a blood test.
Unfortunately, standard assisted reproduction techniques are no cure for low egg reserve. Pregnancy and live birth rates for traditional IVF cycles with own eggs do not differ much from those achieved as a result of natural conception. It means they’re equally low. In this case, donor eggs are the safest way to ensure a pregnancy.
Among other potential candidates for egg donation, there are fertility patients with previous failed multiple IVF attempts and women carrying transmittable genetic abnormalities (although the latter has declined with the development of pre-implantation genetic diagnosis – PGD). Obviously, the indication for egg donation is also ovarian failure caused by surgery (e.g. removal of ovaries) or chemotherapy.
Donor eggs can come in two forms – fresh and frozen. When using fresh eggs, doctors try to synchronise the cycle between the donor and the recipient. The egg donor receives hormone injections to induce ovulation and get multiple eggs. At the same time, the recipient starts a substituted cycle where she is given a mild hormone replacement treatment to prepare the lining of the womb for the embryo transfer. Frozen eggs, on the other hand, are retrieved and frozen in advance. Cycle synchronisation between the donor and the recipient is not needed – the eggs are thawed, get fertilised with IVF or ICSI and the resulting embryos are transferred within the patient’s natural cycle. The treatment is simpler, faster and allows more time for additional testing – whenever it is needed.
But up to recently, frozen egg donations did have their disadvantages. Most importantly, it was quite difficult to retain eggs’ good quality after being thawed. However, everything changed in the mid 2000’s, when a new method of preserving human eggs was developed – namely, vitrification. It is a much faster process than the previously used ones and a result, it may cause less damage to the eggs. Vitrification significantly improved the survival rate of oocytes and led to pregnancy and live birth rates comparable to those achieved with the use of fresh oocytes.
The egg donor selection
Choosing an egg donor is probably one of the most complex – but at the same time most fascinating – processes in the whole egg donation treatment. Patients generally approach it with lots of doubts and questions, among which the most common one is ‘Will the baby look like me?’. It has to be started clearly that all donor selection processes are always based on phenotypic characteristics and genetic matching. Choosing an egg donor starts with phenotype matching during which doctors make sure that the donor resembles the intended mother in all the important characteristics, such as skin colour, eye and hair colour, facial features, body type, height and weight.
The donor should generally be younger than 35 years old and have no indication of impaired fertility. She undergoes a thorough medical evaluation, including testing for communicable infectious diseases (e.g. hepatitis, HIV, syphilis), genetic screening and karyotype analysis to rule out cystic fibrosis, sickle cell disease, thalassemia and other genetic anomalies that could be dangerous to the child. A formal psychological evaluation is also performed.
Despite all those precautions, we have to remember that egg donation is not a guarantee of euploid (chromosomally normal) embryos. The only solution for that is preimplantation genetic testing (PGT) of embryos Only in this way it is possible to rule out any genetic abnormalities completely. However, the latter is not medically indicated in all the cases.
Anonymity vs. non-anonymity rule
When choosing the clinic for your egg donation treatment, you have to be aware that different countries have different laws in regards to egg donors. Anonymous egg donation is practised in most European destinations. In this case, an egg donor is chosen with the help of your fertility clinic. The clinics have their egg donor base where you can see all the information available on donors, namely their height, weight, age, skin, eyes and hair colour as well as education and profession. Neither you nor the donor can learn each other’s personal, identifying data. The egg donor has no parental rights to the child either.
In the UK, where egg donation is non-anonymous, egg donors must agree to be identifiable to any person conceived from their donation. Children born through donation can learn the identity of the donor once they reach the age of 18. The identifying information includes egg donor’s name, NHS number and last-known address. The recipients can also find out how many other children have been born following the donor’s donation, their gender and year of birth.
Deciding on a non-anonymous or anonymous donor is all up to you. When making the decision, weigh all pros and cons and think what would be the best option for your future child. But regardless of the egg donation type you choose, you have to remember that being truthful with the child is the most important – even if the donor is anonymous. Above all, it allows to establish an accurate medical history for the child in case of potential health risks or life-endangering situations in the future.
It may be overwhelming to learn that your only chance of becoming pregnant is by using donor eggs. Many patients struggling with this life-changing decision experience all sorts of emotions and concerns. They have doubts whether they will truly feel that the child is theirs, if the ‘difference’ will be a problem and how they will approach the discussion about the way the conception took place. Surely, all these implications have to be thoroughly thought over to help you decide whether or not donor conception is the right choice for you and your family. Using donor eggs will obviously redefine your perception of parenthood. But however challenging it may seem, it can, in fact, help you realize that the best parts of you are not necessarily genetic traits. These are your personal qualities as well as love and care that will be of greatest importance to the relationship with your future child.