During this live Q&A, our experts discussed IVF failures, what could have gone wrong, and the next steps you can take to move forward with hope and clarity.
Featuring experts:
The event was hosted by: Professor Alan Thornhill, Fertility Expert and coach and founder of The Fertility Guy.
Dr Ángela Llaneza, Clínica Tambre: I’ve been working in the IVF field for almost 10 years. I’m the Scientific Director of the Clínica Tambre in Madrid. Tambre has been operating for almost 40 years and was one of the first clinics in Spain.
Our main area of focus is difficult cases. We have extensive experience in low ovarian reserve and implantation failure. To better support our patients, we’ve upgraded our lab with the latest technology and actively participate in research through the Tambre Foundation. At the moment, we are working on multiple projects, including those involving AI, to increase the success rate per transfer—directly related to today’s topic.
Regarding your question, the main question would be—and I assume the answer is no—whether those embryos were tested. After 38, we strongly recommend testing embryos. The embryo is the key factor in both failures and successes. Without PGT-A testing, diagnosing implantation failure wouldn’t be entirely accurate. My main advice would be to run a new cycle with PGT-A testing. Once we have genetically normal embryos, we can explore additional testing to rule out other possible causes of implantation failure. The first step is definitely to test the embryos.
Professor Svend Lindenber, Copenhagen Fertility Center: I’ve been working in IVF for 40 years. I did the first IVF baby in Denmark back in the 80s and have been conducting research in the field ever since. The clinic I currently lead was founded 20 years ago, but its roots go back even further, with much of our staff having been with us for decades. We focus on implantation failures and have been working in this area for many years. We use a lot of mild and low stimulation approaches for difficult cases and have a strong interest in repeated implantation failures.
We are part of a larger group called Eugin, a Spanish organization, although I must admit my Spanish isn’t great. However, we handle a large portion of their research, particularly in relation to the microbiome and its connection to implantation.
Regarding your question, In Denmark, PGT-A is not used very much, and that’s due to legal regulations. It’s not allowed. As Angela already said, it’s a very important tool for difficult cases, but for screening, it’s not very useful. The situation in Denmark is that we do not screen routinely because we might exclude a lot of eggs that could still be viable. However, in difficult cases, it is possible in Denmark—we can do it—but we don’t use it very often because it doesn’t add much in most cases. Only for very difficult cases does it provide some benefit for the patient.
You had double transfers every time, and you’re only 38 years old, which would never be allowed in Denmark. There must be something wrong with the eggs if we assume you are otherwise healthy. In Denmark, we would examine the eggs, and if that wasn’t the issue, we would do a diagnostic hysteroscopy or maybe a biopsy to see what’s going on in the endometrium. However, I fully agree with Angela—test the eggs—because, at that point, the most common cause is the eggs themselves.
Professor Svend Lindenber, Copenhagen Fertility Center: It’s very dependent on how much was done to the myometrium in the uterus. Sometimes, you can actually start after a month or two, but it depends on where the fibroids were, how big they were, and also how obstetrics afterwards would be. Sometimes, it takes up to half a year before you can proceed if a significant amount of tissue is removed from the uterus. Otherwise, small fibromas are of no concern, and you can start almost the month after. It also depends on whether the fibroids were involved with the endometrium or not, so that’s the issue.
Yes, there are clear guidelines for this, and with the experience we have, it’s very easy for a routine doctor to look at the notes and see what was done based on the surgical description. Sometimes, we can even start the IVF procedure the month after fibroid removal, whereas in other cases, we have to wait up to half a year.
Dr Ángela Llaneza, Clínica Tambre: Well, as we know, unfortunately, we have to work with cumulative live birth rates. Even though 3 euploid embryos will provide a pregnancy for almost 70% of the population, we know there is a percentage of patients who will need more embryo transfers.
How can we shorten the time of pregnancy? My advice would be to run all available testing on extra-embryonic factors. That means looking at the immunological point of view and undergoing a full assessment of the peripheral immune system—meaning antibodies, NK cells, and lymphocytes in peripheral blood. Even though we know the evidence is quite low on all these tests, we can also examine what’s going on inside the uterus from many perspectives.
We can look at the uterine factor through a 3D ultrasound or hysteroscopy if there’s suspicion of a uterine anomaly or adenomyosis. Otherwise, I’m not very fond of routine diagnostic hysteroscopies because, right now, genetic testing on endometrial biopsies provides more accurate information.
What does this type of genetic testing look like? It mainly examines 4 things. One is the microbiome—we get a full view of the patient’s microbiome and can provide specific treatment if needed. We also check for chronic endometritis by identifying pathogenic bacteria, not just plasma cells, as we would with a hysteroscopy. Additionally, we assess endometrial receptivity—though the evidence is quite low, this is still the most accurate test we have right now. Lastly, we examine NK cells inside the endometrium. With immunological testing and endometrial biopsy, we get a comprehensive view of extra-embryonic factors. Also, we can’t forget that the most significant thrombophilia issues that can cause problems are autoimmune-related—like antiphospholipid syndrome—so we look at standard antibodies as well.
Once we transfer euploid embryos, we know the embryo is the key factor. We need to continue transferring embryos, but we can also explore different types of endometrial preparation and run all available complementary testing. Even though the evidence is weak, we still need to help this patient. If needed, we could consider trying for a new round of embryos. We could also discuss immunological phenotyping and matching with a donor—or with both donors in the case of double donation.
It is very unlikely that we’re going to find something, but we’re trying to provide psychological reassurance. The main thing that I say is: listen, if we were strictly following clinical guidelines, I would just be transferring embryos one after the other, and eventually, we would achieve a pregnancy. But obviously, that feels frustrating for both sides—for me and for the patient. We need to discuss different types of strategies and different types of testing.
I’m not very fond of it, and I rarely do it before undergoing all complementary testing, but we can also discuss double embryo transfer. However, transferring 2 euploid-tested embryos carries a high risk of splitting, so we do not advise it. That could also be discussed as a strategy to increase the success rate per transfer.
Professor Svend Lindenber, Copenhagen Fertility Center: Angela is saying that if you have had 3 transfers of euploid blastocysts, 70% of your patients will be pregnant, but you still have 30% who are not pregnant for no known reason. If you continue, you will still have pregnancies.
Keeping that in mind, there are several tests Angela mentioned that would never give me any guidance because the evidence for them is so low. So, they cannot be used. We can use them as tests for the clinic in the long run to gain more knowledge, but having patients pay for them would never be allowed in Denmark.
In this case, I would look at either a biopsy to examine the microbiome and genetics, specifically plasma cells, as well as thrombophilia and similar factors. These are things we have already screened for before patients even enter the system, so it’s not worth repeating.
You have to realize that many of the tests Angela mentioned, like NK cells and similar things, we have been doing for many years, and we have never seen any positive effect—only casual, sometimes. But in the long run, in Denmark, we need to keep costs down because patients don’t see the value for the money.
In our clinic, we would re-evaluate endocrinology, examine the morphology of the endometrium, and perform some of these tests. By doing that, we would focus strictly on those and not go too far beyond. Remember, many of the tests offered for endometrial receptivity are worth nothing. So, you need to be very careful when adding them for patients. We are very close to what the UK Add-On system is using, where we must be cautious about what we are doing.
On the other hand, there is this demand from patients—”But there must be something, doctor.” We always have to remember that many of the tests we offer with very little evidence are only for research or to provide psychological reassurance to the patient.
In our clinic, we are not allowed to do things where the evidence is not clear. It’s simply not allowed in Denmark. In that sense, we are a little bit more primitive. But I agree that there are a few tests that can be done. However, performing the whole panel just for the sake of it would be insane because it does not guide the patient—it only makes us all more frustrated.
Professor Svend Lindenber, Copenhagen Fertility Centre: Assuming you have already checked the endometrium and everything looks fine, then we should investigate the male factor.
In Denmark, we are allowed to perform double donations. For years, we have said that sperm quality and paternal age don’t matter much—but in some cases, they do. We can perform DNA fragmentation tests and other assessments. In some cases, double donation is worth considering. The older the patient gets, the bigger the challenges become. Another important factor is whether the embryos were transferred at the blastocyst stage and whether they underwent PGT-A before transfer.
Dr Ángela Llaneza, Clínica Tambre: We don’t perform egg donation treatments without karyotyping because we don’t want to miss an abnormal result. I would assume the male partner has already been tested, but it’s worth confirming.
We also need to consider the male factor and advanced paternal age. It’s difficult to establish a strict cut-off, but according to recent evidence, 50 years might be a relevant threshold. After 50, we see 2 major issues. First, increased sperm DNA fragmentation, particularly double-stranded DNA fragmentation. We can test for this and use advanced sperm selection techniques to reduce the risk of working with highly fragmented sperm.
Second, we see an increase in what we call de novo mutations in embryos, which in some cases can be lethal. These mutations can only be detected through whole-genome sequencing, which is not routine but could be considered in specific cases. I would recommend PGT-A to rule out abnormal embryos. However, there’s no clear test that tells us whether the prognosis would be better with a sperm donor.
At this stage, the numbers we see here are quite normal. Most patients undergoing egg donation need at least 6 embryo transfers to achieve pregnancy. Cost-wise, the couple may need to consider whether they want to continue with the current approach or switch to sperm donation.
Regarding the age limit in Spain, we normally try not to create embryos after the patient turns 51.
Professor Svend Lindenber, Copenhagen Fertility Centre: In Denmark, the limit is 45. We are not allowed to do any fertility treatments beyond that.
Dr Ángela Llaneza, Clínica Tambre: Well, not really, but what catches my attention is that both embryos were on day 6 and day 7. Obviously, we know that sometimes embryos are slower, and it is normal for a blastocyst to be fully formed between day 5 and day 6.
You want most of your blastocysts to be frozen or transferred on day 5. So actually, that’s something we would need to address, and we would want to fully assess the oocytes. You’ve had embryos, and it’s only 1 round, so I would give it another go with a new round.
We’re going to look into the protocol, and we might want to implement what we call double stimulation—doing 2 stimulations in a row, trying to benefit from the luteal phase.
The second stimulation, we know, on average, is going to provide 1 to 2 extra eggs, which are going to be 1 to 2 extra chances. Some research also tells us that maybe eggs coming from the luteal phase, the second stimulation, might have a higher chance of becoming a healthy embryo. With an individualized and tailored protocol, I would give it another go.
Professor Svend Lindenber, Copenhagen Fertility Center: No, we very seldom freeze on day 3. The results are not very good.
Sometimes we are forced to do it, and I will come back to why we do that. Freezing blastocysts and culturing to the blastocyst stage is excellent, so why should we freeze on day 3?
There are very few reasons. We have a small number of patients who come back after having done IVF with us before when we used the old slow-freezing method, and they had pregnancies with that. There are a few patients who never develop blastocysts, but have excellent results with day 2 or day 3 transfers. In those cases, we sometimes do it.
Normally, we do not advise patients to do this. It’s not a good approach, and I think by doing that, you are reducing their chances a lot. Now, with the knowledge we have today, it’s just not the best option.
Regarding transfer on day-3, it’s a bit controversial, but in Scandinavian countries, we have a long tradition of doing it. The big problem here is that I know the Spanish way of doing IVF is very different from the Scandinavian way.
In Scandinavia, we typically retrieve only 4 to 6 eggs per IVF cycle, which means we have very few eggs. By doing that, we almost select the embryo on day 2 or 3, so at that time, we can already say which one is the best.
If there are more, we just leave them to develop to the blastocyst stage and freeze them. By using that strategy, we haven’t seen any significant differences in cumulative pregnancy rates whether we transfer on day 2, day 3, or at the blastocyst stage.
If you want a quick pregnancy, of course, transferring a blastocyst is the way to go. But in terms of cumulative pregnancy rates, it’s similar.
You must also remember that we have a lot of patients from abroad who cannot stay in the country for many days. They want to go back quickly, so they prefer early transfer.
The strategy of culturing to the blastocyst stage and then doing earlier transfers for the best embryos works equally well. That’s what most clinics in Denmark do, although we now tend more and more to perform blastocyst culture whenever possible, even when we have few eggs.
Dr Ángela Llaneza, Clínica Tambre: We don’t do day 3 embryo transfers, unless it is very, very discussed and agreed with the patient. However, we don’t do day 3 embryo transfers because if you’re not going to get pregnant at the end of the day, I want to have information on both sides and also on the main factor. I want to see how those embryos behave from day 3 onwards. Unless it’s required by the patient and agreed upon, we won’t be doing day 3 embryo transfers.
Dr Ángela Llaneza, Clínica Tambre: I wouldn’t run any complementary testing on the embryos. In research, we have run some tests with embryos that had been frozen as blastocysts—not on day-1 embryos. We’re talking about solid, resilient, and resistant blastocysts. Even after post-re-biopsy, when comparing results between euploid embryos and embryos that had been biopsied, studied, and then frozen, versus those frozen without biopsy, the success rate was lower. We know that all this manipulation might have an impact.
Here in our research, we were talking about blastocysts. On day one, I would just try to keep them in culture at least until day 3 and then transfer. If feasible—she’s 40, and if she doesn’t have any pre-existing conditions—a double embryo transfer on day 3 could be discussed.
The main suggestion would be to try to get PGT-A on those embryos and have some diagnosis before transferring. Even though she responded nicely to ovarian stimulation if I remember correctly—24 and 17 oocytes—sometimes in this context when we retrieve many eggs, we have more trouble finding a good embryo. Stimulating the body to retrieve many eggs doesn’t always mean we get many viable embryos. A PGT-A could be useful to further discern and select a healthy embryo.
Right now, if she cannot change the situation, I wouldn’t waste money on further testing of those embryos. Try to go for blastocyst culture. If not, discuss a day-3 embryo transfer and the possibility of a double embryo transfer.
Dr Ángela Llaneza, Clínica Tambre: Right now, in Spain, it can only be used in a research context, not as a standard PGT-A using trophectoderm biopsy. We would need to do both to have a full confirmation of the chromosomal status of the embryos. It is very promising, but for now, it can only be used in research.
Professor Svend Lindenber, Copenhagen Fertility Center: We’re looking into it. We’re doing studies, but it’s far from a routine procedure at the moment. It’s very attractive from an academic perspective, but it’s not something we can offer to patients yet.
Professor Svend Lindenber, Copenhagen Fertility Center: There are a lot of causes. Although you’re looking at the eggs at retrieval, there might be a predisposition in the stimulation protocol or the way they are handled. We teach a lot of young doctors how to do the right type of stimulation—not down-regulating too much or making mistakes.
The timing of oocyte collection is also a factor. You can retrieve excellent eggs, but if they are not activated, you won’t get good embryos. Bad culture conditions, temperature fluctuations—there are many things to look into.
That’s why you need a very well-optimized lab. When we see what we call “bad embryos,” we carefully check if there were any temporary errors or mishandling. We even assessed which embryologist was responsible at each stage.
On the other hand, something is interesting about so-called “bad embryos”—a little bit of fragmentation is better for implantation than a clear four-cell embryo with no fragmentation. That has been known for years. So it depends on what you’re looking at, and there are many factors to evaluate before assuming the embryos are inherently “bad.”
Dr Ángela Llaneza, Clínica Tambre: The answer to both questions, strictly speaking, is no. No general guidelines advise PGT-A testing on donor eggs, and no studies have proven that immunological testing like HLA-C and KIR typing improves outcomes.
However, when experiencing multiple failures, we know that PGT-A increases the success rate per transfer. If you’re questioning what’s going wrong—whether it’s just cumulative live birth rates or something else—you may want to confirm that the embryo is chromosomally normal. While the odds of aneuploidy in a 25-year-old donor are low, they are not zero.
If you’re going for a new round of double donation and creating a fresh embryo cohort, changing the donors is an option. Immunological testing and donor matching can be done, but it adds to the cost.
At the end of the day, the key recommendation—especially if the patient has a specific genetic background—would be to do a single embryo transfer, which is generally advised anyway. If I had to choose one thing to do, I would prioritize a single embryo transfer and PGT-A testing for at least 1 or 2 embryos.
Professor Svend Lindenber, Copenhagen Fertility Center: It depends on how you look at it. If you consider new patients coming in, we never do it—there’s no evidence supporting it. If a patient comes in with a test already done, we review it, but we don’t routinely recommend it. We are currently conducting studies, and we have a whole lab working on this.
If a patient has a high DNA fragmentation index, we first try to improve lifestyle factors—stopping smoking, and reducing weight—but these recommendations are generally given regardless of the fragmentation test result. If fragmentation is high, we typically perform ICSI. However, I must say that, at the moment, this does not provide significant benefits for most patients.
If we identify high fragmentation, we address it and try to optimize the situation. As Angela already mentioned, there are purification techniques to filter out fragmented sperm. Some scientific papers support these methods, and we apply them in select cases. However, we do not place too much emphasis on it because, in the long run, it does not add significant value for most patients.
Each test has its own threshold. If you look at the Comet assay, it’s one measure; if you use staining procedures or flow cytometry, it’s different. Some tests consider 7% very high, while others see 2% as low. It depends on the test, the lab, and how they define high fragmentation. Additionally, fragmentation levels vary over time, so results must be interpreted carefully.
Dr Ángela Llaneza, Clínica Tambre: Right now, the test we use to assess fragmentation is the Comet test, which studies both single-stranded and double-stranded DNA fragmentation. Single-stranded fragmentation might be physiological and not very concerning, whereas double-stranded fragmentation could impact outcomes because the oocyte may not be able to repair it.
There is an ongoing debate around fragmentation testing. Additionally, the test is performed on a sample that is not the same as the one used for fertilization—unless we are working with frozen sperm, which we frequently do. If the fragmentation is not too severe, we proceed as usual.
In my lab, we use the TUNEL assay, which does not differentiate between single-stranded and double-stranded fragmentation. If we detect high fragmentation, we add a selection technique. If working with a fresh sperm sample, we use a Chip Fertile technique, which functions like a trap to retain fragmented sperm. Fertile Chip can be used with both fresh and frozen samples. If using frozen sperm, we apply the Sperm Slow technique, which uses microfluidics to eliminate fragmented sperm. While the evidence is limited, we aim to optimize results and maximize the number of viable embryos for patients.
We are conducting extensive research on sperm fragmentation and obtaining remarkable findings related to embryo ploidy. This research is being submitted to ESHRE. My advice is to run this test, especially in cases of repeated failure. I don’t see many patients coming in for a first embryo transfer or cycle at 35—most have undergone multiple failed cycles and significant emotional distress. A thorough discussion with patients about the pros and cons of each approach is necessary. In my opinion, fragmentation testing and sperm selection techniques should not be ruled out based on cost alone and should be universally used.
Dr Ángela Llaneza, Clínica Tambre: I think we’re going to agree on this. It is an experimental technique that has not been proven to improve results. I’ve done it, and we offer the technique because, at the end of the day, you want to do something to try to improve the reserve. But PRP does not help with that. However, it is safe and doesn’t have any downsides because we do it on the day of retrieval.
Sometimes we do it, but we don’t encourage it. It’s when the patient asks for it. If we do it, the cut-off is 40 because after 40, and 41, in our own results, there wasn’t any improvement. We do it in a double stimulation—on the first retrieval—to see what happens on the next. But right now, we cannot say that it is doing anything. We don’t encourage it. If you ask for it, we might discuss the pros and cons and do it.
Professor Svend Lindenber, Copenhagen Fertility Center: I fully agree. There’s a lot of academic interest in this, and also in some of the labs in Denmark are doing ovarian cultures, taking biopsies, and activating ovarian strips.
It seems that it might work in some way by transporting the very primitive follicles to a slightly later stage, but it has never been shown on a larger scale. The problem is that if you look at all the available literature—we just went through it again—it’s awful. It’s badly done, and there are no signs of any benefit at all.
There might be some evidence of benefits in the endometrium, in Asherman Syndrome, where you have endometrial scars and try to loosen them to stimulate the growth of endometrial tissue, reestablish the womb, and restore endometrial surfaces. There might be some benefits there. And I can tell you, the best place to put it is in the knee after knee surgery—you avoid a lot of adhesions by doing that.
Put it in the knees—that’s only 30 cm from the womb and ovary—maybe it works there. But in the ovary? No.
Professor Svend Lindenber, Copenhagen Fertility Center: I never start with the age because a woman comes in with some kind of need for a baby, and then you have to address that first. If you then look at a very low AMH, very few antral follicles, and things like that, you will go for advice and feel the sense of, “Is this good enough, or should we go for oocyte donation programs?”
The problem is, in our country, lots of women want to have the last chance just to see—”Is it really true what the doctor is saying, that there are no eggs?” Sometimes we start a cycle doing stimulations just to prove to the woman that there are none. And sometimes we get very, very surprised. Most of the time, we are right, unfortunately.
Sometimes we are doing IVF and try to do it, although we know that the chances are very low. But this is, as Angela is saying, having low responders coming from other clinics, and they end up in our clinic. All these clinics, old clinics, they have all these difficult cases. You try to do it. In many of them, we try mild stimulation, which seems to be a little bit better than just high stimulation. In the end, a very difficult case—we always offer them oocyte donation because it gives them a 68% chance of getting a pregnancy in the first donation program. It’s such a difference from 2 to 3%. They need to at least know.
We had such patient who was 45 years of age. We’ve had one. Definitely with her own eggs. We also had a 45-year-old spontaneous pregnancy after IVF many times. I can tell she came in, and I can tell you it was spontaneous. The chances are very, very small.
Dr Ángela Llaneza, Clínica Tambre: 44. I’ve had 5 patients succeeding at 44.
Dr Ángela Llaneza, Clínica Tambre: That depends, and that changes from patient to patient. There are several things we can use, from the most standard and well-known low molecular weight heparin, Clexane, aspirin, steroids, to some more complex things such as immune modulation drugs, such as Tacrolimus, such as Plaquenil, Hydroxychloroquine.
Then going to more easy, soft things—subcutaneous progesterone—it is very important to have very good progesterone levels. They have very great research on that coming from Denmark. I’m very fond of and a big fan of the HCG Ovitrelle subcutaneous injection in the post-transfer period. Those are very easy things that you could just use.
When it comes to lifestyle after the embryo transfer, just a quick message—this is very stressful for the patients, and all of the research tells us that the activity after the embryo transfer won’t have any impact. Right now, we have pretty accurate data measured with Iwatches and Fitbit about the activity after the embryo transfer. We always encourage you to try to lead a normal life after the embryo transfer and to try to have your mind and your body busy to let those 10 days, in our case, fly by as quickly as possible.
We have several add-on treatments that we could use—maybe more heavy ones, more standard ones, and regular ones. A good progesterone subcutaneous injection at least once a day, and Ovitrelle. I don’t know if you use it, but it’s also something very easy, safe, and cheap.
Professor Svend Lindenber, Copenhagen Fertility Center: I fully agree. I’m personally very fond of Ovitrelle. A small injection, small doses, every one day or every second day. It can drive the whole luteal phase if you want to do that. Two clicks of Ovitrelle every day or every second day runs the luteal phase. Maybe it affects the endometrium. It’s highly debated at the moment, but at least it does not harm the patient. If they’re not hyperstimulated, and you have problems there, the only problem is the pregnancy test when you end up there, because it cross-reacts with a normal pregnancy test. You need to be careful there. But otherwise, I fully agree with these aspects.
Professor Svend Lindenber, Copenhagen Fertility Center: Well, embryo arrest can be a sperm factor, certainly, and it’s a little bit earlier. But in humans, it looks like the maternal genome is changing over day 1 to 2, maybe day 3. So it is something you have to worry about, and you have to look at what you can do about it because we know the prognosis is very bad—very bad.
There are some pregnancies if you transfer. There have been reports of transferring eggs at the 2-pronuclear stage and getting them into the womb, where the environment is better. The prognosis is very bad.
My suggestion is to look at them, because, of course, you would probably change the whole approach if you’re doing oocyte donation. Sometimes sperm donation is easier. At least, what we are doing in our clinic is this: if you have 10–15 eggs—which is a lot in our clinic—you can take 5, something like that, and inseminate them with donor sperm. Then you look at what’s going on.
You do some kind of diagnostic IVF procedure. You can even freeze these eggs if they want to use them later if the other option doesn’t work, so they’re not lost. That would be my suggestion in this case.
Dr Ángela Llaneza, Clínica Tambre: No, I fully agree with the mixed fertilization with the sperm donor and the male partner. How do you feel, Svend, about conventional IVF? Does it provide any benefit?
Professor Svend Lindenber, Copenhagen Fertility Center: No, we are doing it, but all the literature tells us it doesn’t work. But sometimes, we are doing it—maybe we are lucky to get better sperm by doing that. There’s not too much around it, but we are sometimes tending to do that.
But as I told you before, sometimes medical doctors are squeezed into giving patients a solution when we do not know the solution ourselves. So I would go for split insemination and fertilization, which I think is the best approach.
