The importance of making an exhaustive selection of donors

Esther Marbán, MD
Gynecologist & Fertility Specialist , Clinica Tambre
Selection of the donors and its importance
From this video you will find out:
  • What are the selection criteria for egg donors and sperm donors?
  • How is the selection made?
  • Are donors anonymous in Spain?
  • What about genetic matching?
  • Is Fenomatch used in the process of patient-donor matching?
  • What is the process of the treatment using a donor?



All you need to know about sperm and egg donors

In this webinar, Dr Esther Marbán, Gynaecologist & Fertility Specialist at Clinica Tambre, Madrid, Spain has thoroughly explained what egg/sperm donor selection process looks like and what is important to check.

Egg donor selection

Dr Marbán started her presentation by explaining all the steps and criteria that need to be met to become an egg donor in Spain. The first selection criteria for the donors are that they should be up to 30 years old, the minimum height is 1.5 meters, and the maximum Body Mass Index should be 30. The first visit is performed with the nursing team in which an anamnesis will be done, and any medical conditions, as well as familial diseases, will be discarded. The nursing team will explain what the process looks like, and an interview with the psychologist will be done, including a physiological test to discard any psychological diseases or conditions. Later on, some medical tests will be done starting with a general health check in which a complete blood cell count will be included as well as blood type and other blood tests such as serology, then the gynaecological test will be performed in which ultrasound, and AFC (Antral Follicle Count) will be checked, a smear test and vaginal swab to discard an infection. Apart from those general tests, some genetic tests, including a karyotype, will be performed. Other genetic tests include the most common diseases such as cystic fibrosis, X fragile, basic recessive mutation, etc. All donors need to do a Carrier Status Test of more than 300 genetic illnesses to reduce the genetic risk that the patients may have.

Sperm donor selection

Regarding the sperm donors, the selection is almost the same. The first criteria are the age, they have to be 35 years old or under, the minimum height is 1.70 m, and the Body Mass Index is 30. During the first consultation with the andrology team again they check if there are no medical conditions and familial diseases, then the psychologist will do the examinations to discard any psychological problems and some medical tests will be performed. The general health research is the same as in the female donors, but some andrological tests, including sperm count, sperm and urine cultures, and PCR for chlamydia are checked. The genetic evaluation is the same as with the egg donors.

The selection of the donors is always done by the centre to respect anonymity. It is based on different steps, such as physical characteristics, blood type, a special program called Fenomatch, doctor-patient communication, and in some specific cases, immunological matching (KIR HLA) and genetic matching.

Egg donation treatment

One of the most common treatments is egg donation. There are two different parts of the process, the egg donor has to follow all the steps as well as the recipient. As mentioned above, the donors have to be 30 years old or under with no reproductive problems, the psychological assessment is also required. In Spain, the donation is anonymous, but the medical team of the clinic always takes a picture of the donors to use that photo in the future. The egg donor has to be phenotypically matched with the recipient, and then the eggs are retrieved. The cycles are synchronized between the patient and the donor, it’s best to do both treatments at the same time so that the patient doesn’t have to wait for a long time until the donor performs her stimulation. The patients will do an endometrial preparation for the embryo transfer.

Donor sperm treatment

When we’re talking about the idea of treatment with donor sperm, the main indications are: failure of artificial insemination, advanced maternal age, pathology of the fallopian tubes, severe male factor, the need for implantation genetic screening, and this is a treatment suitable for single mothers or same-sex female couples. What about the physical characteristics? At Clinica Tambre, there are more than 2 500 samples stored in the bank respecting very strict security rules, and there is a wide range of phenotypes. There is no waiting list even though almost all the physical characteristics are available. That means the patients will have a greater chance of finding a perfect donor.

The first step of donor selection starts with documents that the patients need to sign. The document includes the patient’s characteristics and consent form of treatment, with a photograph of the patient.


Fenomatch is a facial mating with a scientific tool that uses biometric technology to identify facial point distances. It allows a very accurate selection of the donor regarding concrete facial features. Using a photograph of the patient’s face, the algorithm scans more than 12 000 data points to find the donor with the greatest biometric similarity. This means that the donor-conceived children are more likely to look like their parents. The donor with the highest score and the most suitable one is chosen. The patient receives a report certifying the use of Fenomatch during the selection process.

Take home messages

  • There are no ‘good’ or ‘bad’ donors, but compatible donors
  • Therefore, not only the physical characteristics are important, but also the compatibility
  • Not all the clinics do the same pre-screening of the donors, the patient needs to have all the information about it to make a good selection
- Questions and Answers

What could be the problem if some blood is collected from the egg donor before the egg retrieval? Can egg retrieval be done? I’m asking because there was blood collected just before egg retrieval of one of my donors?

Possibly that donor had a complication during the surgery, and well, they might have complications which are not very likely to happen, but we know that when we do an egg retrieval, we’re going to harm the ovaries at any point. Sometimes, the amount of blood that can be inside the belly can be quite high, and it’s not very likely to happen, but of course, these are the risks that donors take when they donate. Sometimes, that complication may happen, but they are very uncommon, of course. We do take care of our donors apart from doing the procedure according to the protocols, we always phone our donors after doing the egg retrieval. We call them also the day after doing the egg retrieval, and then we always do a vaginal scan in about one week after doing the egg retrieval to make sure that everything is fine with them.

Can you use your own donor in Spain?

In Spain, it’s not possible because the donation is anonymous, which means that the patient won’t know who the donor is. It is not possible to choose or bring your donor to the clinic because it wouldn’t be anonymous in that way.

Can I choose the gender of the baby and that the donor is Spanish? Also, do you do Fenomatch for both: egg donors and sperm donors? Will the donor remain anonymous when the child turns 18?

We use Fenomatch for both donors and the egg and the sperm donors. Regarding choosing the gender, in Spain, it is not possible according to the Spanish reproduction law. When it comes to the anonymity of the procedure, it’s not possible to choose and to say that you want a Spanish donor. The selection is not regarding the nationality of the donor, it’s regarding their race and skin color, hair color, and so on, so we consider the physical appearance, not the nationality of the donors because, in the end, the important thing is to find a suitable donor for the patient.

Regarding the sperm donor criterion. Is IQ or other measures of intelligence considered? Can you explain more about the mental screening processes in Spain? For example, a history of depression, etc.?

There is no specific intelligent test that is done by the psychologist. The psychologist performs a very personalized interview in which some specific questions are asked about the diseases in the family, especially mental diseases such as depression, schizophrenia, and so on, and some background of mental diseases. Then, depending on the donor, sometimes some specific psychological tests are performer to discard any mental problems, so indeed is a very wide examination that is performed by our psychologists.

With 2500 samples in your bank, what’s the percentage of Southeast Asian origins donors do you have?

Actually, we have donors with all the different characteristics, but it indeed depends on the patients we have. The most common patients we have are Caucasian, but of course, it depends on the patient. It’s very hard to tell you exactly the percentage of Southeast Asian donors that we have because not all the patients are the same. We prefer to know the patient, to meet the patient to know if we have a suitable donor for her to say if she wants to go with us if we can and use a very specific donor and if we are able to find someone who looks like her or like him.

I am of mixed race (Filipino and Caucasian). My boyfriend had a vasectomy, and so I will be using donor sperm. If I include him in the process, then I can request a Caucasian donor because he also is Caucasian? However, it is not important to me if his physical characteristics are considered in the donor selection process. Can you comment on whether I need to include him in the process in order to have a Caucasian donor?

According to the Spanish reproduction law both donors, I mean the sperm and the egg donor have to look like the mother. If the patient is Caucasian, both donors have to be Caucasian, but if, for example, if you’re Filipino and the partner are Caucasian, both donors have to look like the patient, so this is what the law says, and we need to follow that. We can’t use a Caucasian donor unless the patient is Caucasian, so it’s important to know that the Spanish reproduction law says that both donors have to be similar to the mother. In that situation, if you’re Filipino and your partner is Caucasian, both donors should look like you, in the end.

Do you exchange samples (eggs and sperm) with other banks (hospitals in Europe)?

Actually, it’s not an exchange, so for example, in Madrid, many public hospitals that need a sperm donor request the sperm donor from our bank because our sperm bank was the first sperm bank in Madrid, so actually, we share our samples and our donors with different public hospitals. In case we have a request from a different place, we will consider it, but in general, all our donors are used in public hospitals here in Madrid.

How do you create the egg donor database? And do you only use your own or collaborate with other clinics?

We have our own egg and sperm banks, so we do not collaborate with other clinics. Our database is based on the physical characteristics of the donor. As I mentioned before, we have pictures of our donors, and we have a complete document with information on them. We have all the tests that were done, and we have all the genetic information about the donors, which is something important to consider as well. We know who our donors are, and we know them perfectly well, so it’s a good thing to know because in other clinics, maybe the computer is going to do like matching between a patient and a donor, but in our clinic, Clinica Tambre, it’s like a team with different nurses and doctor, the ones that decide what donor could match with the patients apart from the Fenomatch and other selection that we mentioned before. That’s the way we normally work.

The mother is of mixed race. Half-Filipino and Half-Caucasian.  My partner is Caucasian. It would not make sense as a couple if we had children that the child is as dark as me?

I perfectly understand because I completely agree, but the Spanish reproduction law says that both donors have to look like the mother, and we can’t change the law. If the law changes in the future, it would be great because I completely agree that if a couple is mixed, it is important to consider it, and if the egg donor is going to look like the mother, the sperm the donor should look like the father, but the law is as it is today, and we can’t do anything to change it, I’m afraid.

Do you grade egg quality?

Actually, it’s not possible to grade the eggs. Most donors are fertile, so it means that the egg quality is high, but apart from that, it’s not possible to grade the quality of the eggs. We know that there are mature eggs, which are the ones that are selected to be fertilized, but there is no classification in the egg quality. The quality of the eggs is really related to the age, so if we are thinking that donors are 30 years old or under, the quality of the eggs is really high. Apart from that, many donors are fertile, so it means that the egg quality is high also, but we don’t have any classification to grade the egg quality at this moment at least.

If you can’t find someone with a similar characteristic because you don’t have that many Asian donors. Can the recipient make a selection on their own by looking at the donor’s pictures?

The donation is completely anonymous, so it means that it’s not possible to see any pictures of the donors, it’s completely forbidden by law. What we can do is, for example, if the patient has to wait some more weeks to try to find someone who looks like her, it’s just a matter of talking to the patients and giving that kind of information. In very specific and I would say that quite an uncommon situation, we can try to find a suitable donor in a different egg bank in Spain, but in general, we don’t use that kind of banks because we have our own egg bank, so we don’t need to use a different bank. In the end, if it’s a matter of waiting for the most suitable donor for the patients, we always inform our patients to let them know that we’ll find a suitable donor, but it will take longer than we expected.

How long does the donor selection process take?

If we are talking about the selection of the donor normally, it takes not more than one month. It will depend on the physical characteristics of the patients and the donor that we need to select. For example, if we need a very specific donor, let’s say we need to test the donor regarding the immunological system sometimes, it will take longer. It can then take maybe two months. It depends on the situation, but normally it won’t take more than one month. If the patient has a very specific blood type or physical appearance again, it will take longer.

Do you guarantee a minimum number of eggs /embryos per transfer?

We guarantee both of them depending on the sperm quality. If the sperm quality is normal, we guarantee a number of embryos, so I wouldn’t say embryos per transfer, we guarantee the number of embryos at the end of the procedure. We normally transfer one embryo, but if the patient, for example, wants to have a guarantee with at least two embryos, we always reach that guarantee. The idea is that if the sperm is of really bad quality, in that situation, we guarantee the number of eggs. In general, we guarantee the number of embryos at the end of the treatment to our patients.

For how long do you can keep eggs and sperm in your bank? At what temperature are they frozen?

The sperm and the eggs, and even the embryos don’t lose any quality when being frozen. They can be there for years and years. We have samples that were used many years ago, of course, we are not using them at this moment, but they are there. Luckily, both the embryos, the eggs, and the and the sperm samples don’t lose any quality, and they can be kept for years and years, there is no limit in that way. Normally, they are frozen in minus 196C degrees.

When someone is included in the donor database how are they selected? Education, etc.? How is a woman incentivized if at all, to become a donor? What’s in it for her?

We did research on that two years ago, and we asked our patients at that moment why they decided to donate, and the main reason is helping other women. It was the main reason why donors decide to donate, so some of them may have some friends or relatives that suffered from infertility in the past, and they are quite used to that kind of problems, and the main reason is helping other women to become a mother. We are lucky in that way because they don’t mind to take some risks to try to help other women to become a mother, so in the end, they do a great job, they let us and help other women. If we didn’t have our donors, it would be impossible to keep on doing so many treatments and helping so many people.

Is there a maximum number of donations? How many times can you use each sperm donor per country?

The maximum number is six donations in our clinic. The Spanish reproduction law allows the donor to donate until six pregnancies, so six babies born in the same country, so it means that, for example, if the donor donates, let’s say four times, and there are in total six pregnancies in the same country, she wouldn’t be able to donate anymore. It doesn’t matter if it’s an egg or a sperm donor. If a donor donates several times, but there are no pregnancies with those donations, we can keep on using that donor until six pregnancies are reached.

When you mention the age limit of 50, can the patient actually be 50, or do they have to have the procedure done before their 50th birthday or before they turn 51?

It depends on the patient. We recommend to do it before the patient is 50 years old. On some specific occasions, with some specific patients, if all the tests that we perform on those kinds of patients are fine, we can try to do the treatment when she’s like 50 years old and some months, but before she turns 51 for sure. It will depend on the tests and all the medical team opinions, so that kind of patients are discussed during our medical meeting that we have weekly, and we decide if that is a good idea or not. It’s not just a medical decision, you have to consider several different opinions in the team and, of course, the medical tests that should be performed before making a decision.

How important is the blood type match when choosing the donor?

I would say that is the least important thing. The reason is that we know that there is no problem in choosing a different blood type donor, so it won’t harm the baby and it won’t cause any problem during the pregnancy. What we try to do is, for example, if both patients are 0 positive, the baby has to be 0 positive if they have a baby with their own eggs and sperm. But, it’s impossible to have a baby with A blood type if yours is 0, so we always try to match the blood type because many patients prefer not to say that they have undergone any kind of treatment, and they prefer not to tell anyone that the baby came from egg donation or sperm donor treatments. That’s the reason why we match the blood type, it’s different when both patients have a negative blood type, I mean A negative, 0 negative, so it’s important to try to find a negative blood type donor to try to avoid any problems during the pregnancy. In general, the blood type is important, but it’s not the most important thing to consider. Imagine that we have a perfect match donor, but the blood type is different from her. We ask our patient and say we have a perfect donor for you, but maybe the blood type is different so it won’t cause any problem to the baby, and the patients can decide if they want to go on with that donor or if they prefer to wait until we have a let’s say a different donor with the same blood type. It’s not a very common situation because it’s very unlikely not to find a suitable donor because of the blood type but in some specific situations, everything can happen.

What is the live birth success rate with donated eggs at Tambre?

The implantation rate depending on the treatment that the patient will choose, but it is around 65 to 68% in general. Depending on the age and the medical and previous conditions of the baby, the live birth success rate may change, so it’s not the same to get pregnant in the first attempt if you are 40 years old than if you had previous miscarriages, and you are around 50 years old, the live birth success rate may decrease. In general, the implantation rate is around 65%.

Is there a higher success rate of having a fresh transfer over a frozen transfer?

At this moment, both pregnancy rates are almost the same, so in Clinica Tambre, the first embryo transfer is normally done with a fresh embryo, and then the other embryos are kept for the future. I would say that day by day, both pregnancy rates are really close to each other. Nowadays, there is a slightly higher pregnancy rate with fresh embryo transfer than with frozen ones.

How many times do I need to travel to Spain for egg/ sperm donation?

We recommend coming for a first consultation to take advantage and do all the tests that could be needed. Many patients prefer to do all the tests in their home country and just come for the embryo transfers, so I would say that you just need to come once or twice, not more.
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Esther Marbán, MD

Dr Esther Marbán has been part of Clínica Tambre’s medical team since 2010. She is a gynaecologist specialized in Human Reproduction with a brilliant academic career. In fact, she obtained a special honourable mention in her Master’s Degree in Human Reproduction that she completed during 2009-2010 (organised jointly by the Spanish Fertility Society and the Faculty of Medicine of the Complutense University of Madrid). Dr Marbán is known for her restless and proactive personality and her innate talent for empathizing with people which she proves every day by working with patients.
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