Implantation failure and egg donation

First, I would like to comment just shortly about the most common reasons for implantation failure, and it’s in 70-80 % of cases a failure of the embryo. Implantation failure describes the relationship between an embryo and uterine environment, and the clinic should establish a kind of dialogue between both, and the first input always goes out from the embryo. So metabolically, the genetically competent embryo can start this conversation, and then the uterus, and the endometrium usually, only reacts. It is known that about 500 molecular signals are exchanged during the first phase of implantation, but this also means, that 20-30 % of cases of implantation failure we can find the reason in the uterine environment. What does this mean for egg donation patients specifically? So egg donation patients are – from the point of view of the embryo quality – better shaped than normal IVF patients, that have to handle the decreasing quality of their eggs, the increasing age, the increased aneuploidy and genetic imbalance of their embryos, so the critical part for implantation is the embryo quality. So this is how we also learned over the past years and decades about the uterine factors that as mentioned provides 20-30 % of the implantation failures but are very easy to study in an egg donation population. If we can count with 80% of the egg quality already given, we have much more resources to detect small differences in a lot of factors that influence the uterine environment. Just, to mention a couple of them, we will discuss more in detail during the next questions. The first thing for an embryo is to implant. This is a critical time, between getting nutrients from the media where they grew up during the IVF treatment, – even in nature, it’s the same -to get implanted means to get blood flow which means being able to pass this critic time between transfer and implantation. And to assure how to provide themselves with enough blood flow that will bring nutrients later, that will allow to make the placenta and to establish the switch organ, and that will assure the further growth and the supply of nutrients. So this is why blood flow is very important, and we will see in implantation failure cases that usually, the blood flow is diminished. This can happen f. e. if there is a chronic infection like endometritis. If there is a disease like adenomyosis which means there is a chronic inflammation around the subendometrium. Also, in cases of congenital anatomic failures like myomas that interfere in the blood supply of the endometrium. So there could be, let’s say anatomical reasons, but most of the cases are a little bit more depending on hormones, genetics and immunology. We have to understand that fetus and embryo is a foreign body for the mother that has to implant this embryo and nature have foreseen that. There is a special condition during pregnancy that is called immune tolerance where all the machinery fights against intruders, fights against the possible foreign bodies and fights against genetic instances that are different. This immune tolerance means that in the endometrium there is a special condition that allows a foreign body to be accepted and to be implanted, and this is a very suitable and very sensible balance that easily can get these distortions. If the embryo can start this dialogue with the endometrium, the most critical thing that the endometrium has to do is to manage the immunology, manage the hormonal inputs that will allow the embryo to implant, only to a certain time. After 24- 36 hours, this window of implantation gets closed, and then the chance for successful implantation disappears, and in the end, it’s an immunological issue. So in egg donation what we find, is that usually patients with higher age than in normal IVF, and all these qualities f.e. immunology, autoimmune diseases will increase with age, therefore, patients undergoing egg donation are more prone to have such kind of problems. In terms of the displacement of the window of implantation – so the hormonal response of the endometrium – there is some slower activity in women beyond a certain age. I would say around 40 or older where the synchronization between embryo and endometrium may fail, and these are all conditions despite the anatomy which is congenital and applies for everybody that has it but all other threes a higher incidence with increasing age. This is why it is so critical for egg donation patients to be aware of those risk and to adapt protocols to that special situation.

PGT-A and in the past it was called PG, so pre-implantation genetic screening is the technology that can assess the genetic chromosomic formula of embryos before transferring them. This is extremely useful in women who is over 35 that wants a pregnancy with her own eggs up to 43- 44 it is a really strong instrument that has helped thousands of patients in improving their chances. Having said that, does this really apply also for egg donation patients where the donor is quite young? This question is much more interesting because there is no clear evidence so far that there would be more benefits than disadvantages from medical and also from the financial point of view. I would like to highlight a little bit on our experience with that, which is based on transmitting facts. What we know is that human eggs are genetically very unstable, and also in a very young woman like egg donors with high fertility potential they can have the capability of genetically abnormal embryos. In a way, that forms a full court of a cycle, if we test all the blastocysts that the best donor of the world could generate being 25 years old, at least 25% of them would carry some kind of genetic imbalance, which is a lot. This means, the chromosomes in humans are very prone to mistakes, and obviously later on, when a woman is 30 or 35, this could be 50% of all the embryos when she is 40, this could be 80% of all the embryos and being close to 43, this could be 90% or even 100% of all the embryos. Obviously, this accumulation of mistakes is getting worse with age, but this also applies to very young donors. If we take into account that 25% of them will carry some kind of chromosome imbalance, then you can take it as evidence that from 4 blastocysts, 1 will never give you a healthy newborn. So this one will even have the potential to frustrate you because it will never implant, this is what most commonly happens if an embryo is aneuploid. If they implant, the chances to lose this pregnancy are extremely high so the second group would get lost through early miscarriages, and only very few of all the chromosomic formulas will survive, like Down syndrome or others. This is very unlikely to happen because most of them even though do not implant, we have to also consider in terms of the expectations of the time invested, on the psychology of our patients. If it is worth to transfer embryos blindly, having access to the technology of testing them before transfer because this way we could shorten the time to pregnancy, we could avoid unnecessary implantation failures and frustrations but also time and resources that get lost. We could also decrease the miscarriage rates, in a certain way, from 15% to 5% which is a lot, when we will take into account all the suffering which goes behind that. So, we have to evaluate the possibility of performing PGS also on embryos coming from donated eggs just in terms of opportunity and chance. If you look at the financial point of view, the cost of a cryo transfer is usually around thousand to two thousand euros plus the medication, time, the frustration, and so on. Then applying PGS would be reasonable for everybody, as long as the price for PGS is not as high as three or four thousand euros which are the current prices. In our clinic, for a couple of years now we have been investigating a methodology that will lower the cost of the PGS per embryo to a fifth of the normal cost. When it gets affordable, we hope we can offer this soon, maybe by the end of of this year, and we think this will be like a revolution in medicine because we could even do the PGS for free and test all embryos and then we would change the situation that we have now, where we have to justify why we are doing it. In such case, the question will become completely immersed, and we would think about how to justify not doing it if the cost factor is no longer a problem, and there are only benefits in doing so.

So nature foresees that from both sides, from the side of the embryo and the endometrium, that the dialogue for the implantation has to happen under certain circumstances which cannot be prolonged in time. So for the embryo, this means once it has reached the blastocyst stage and it has extruded from the zona pellucida which protects the embryo in the cellular stage, once it has hatched then an embryo can only survive around 24 hours without getting implanted, and the same happens on the side of the endometrium. Once the endometrium grows, it gets transformed by the progesterone which is a hormonal signal given by the ovulating ovary which transforms the endometrium and makes it suitable to implant an embryo. This also happens only under certain circumstances and even after hormonal inputs and triggers that last only for a certain time. The window of implantation that gets open from the side of the endometrium is just 36 hours open. If an embryo arrives earlier in a stage of being hatched and starts sending signals of the dialogue in an endometrium that has not already opened the window, this means that has not turned on the radio to listen to this input of the embryo, then it will never implant. The same happens if an embryo comes too late to the endometrium and then starts the dialogue when the window is already closed, it will never implant and you can try it a thousand times with the best embryos of the world. A displacement of the synchronization of times between embryo and endometrium will always lead to a failure of implantation. So there is not a gradual diminishing, this is like a hundred or zero, this is as black or white, once you miss the window of implantation, the chances for implementation are zero. That is why we have learned that precisely in the group of patients of egg donation where the average age is a little bit higher, the reactiveness of the endometrium to the drops maybe a little bit delayed. We will find a displaced window of implantation in younger women in about 10% to 15 %, in women over 40 we’ll find it in 20% to 30% of cases. It is a pity to miss the knowledge about the exact individual time frame for the implantation that the woman has because if we knew that, we can adapt all the times of the transfer and the drugs in a way that embryo and endometrium meet at the right time, not before, not later. This is how it works and why it is so relevant, and why this is also new diagnostics and a new therapeutic approach from which especially woman being treated with egg donation can take a lot of advantages. In the end, this can contribute to increasing of the statistically significant implantation success.

ERMAP is one of the receptivity tests that are available in the market, this is the one that we have developed and one we prefer, but there are others. Should we recommend it to everybody, we are working on generating financial and social medical models to explore if it’s really beneficial for everybody or a whole population if we would implement the receptivity test for everybody at the beginning of the treatment. So for that formula, you need to know how expensive the test is. We really can take advantages from it, it’s already proven. If applied to everybody, there is a social-economic impact in terms of improving the chances for everybody in a reasonable way, avoiding costs because a transfer that does not implant is a catastrophic situation. Generating an embryo is extremely costly, and we need to consider the time and the effort invested in that, it’s not worth to lose it just by such small detail. If we take into account that even 10% of transfers would not implant just for reasons like missing the window of implantation, the cost that this has if we took thousands of patients is extremely high compared to the cost of performing this thousand tests in advance for everybody. This a more public-medical approach, if we speak from an individual that is looking for pregnancy with egg donation, I would recommend it to everybody because most of those patients already have had treatments before, they already have had implantation failures that never could get analyzed and be fixed properly, and they belong to the group that really has much more chances of finding a displaced window of implantation and then go for the treatment that costs five thousand or ten thousand euros blindly, without knowing if you belong to the delayed or anticipated window of implantation, it’s, in my opinion, a mistake, and for now, we are just recommending it in cases of egg donation for those patients that had 2 failed implantations before, which are most of them. We are very close to implementing it for everybody, once the price gets a little bit lower and, in a second step, this would apply for everybody in all clinics, also with own eggs and also in public services, this is my opinion.

There are a couple of indicators if there is something wrong with immunology. First, the so-called atopic state, so there are people who are very prone to allergies. These people that are very prone to autoimmune diseases, all these disbalances of the immunological system have also an implication in the uterus, and in the implantation for embryos. The way to screen patients for autoimmune diseases is easy, you can take blood, and you can test a lot of factors, usually antibodies against nuclear proteins or mitochondrial proteins or against some enzymes that are involved in the thyroid function, so there is a lot of already detected immune statuses that belong to the group of autoimmune diseases which definitely interfere with the implantation. Some drugs are used against that, we can mention them shortly, so this is immune modulators, immune globulins, intralipids or similar in the autologous immune globulin production, some monoclonal antibodies can block certain cells which are too aggressive. There is a wide range of immune modulators that I have to admit that have not so much clinical evidence or large studies that would support that. Most of them are just tentative, and some of them are more of an indication in clinical studies. Apart from the blood test, what is much more important for us in terms of implantation and pregnancy, is what happens not only in the whole body that could be an indicator that something is wrong also in the uterus, we can also look what is happening inside the uterus itself, and the way to assess that, is taking a biopsy of the endometrium. We offer this as an immunologic mapping. There are other technologies like flow cytometry (FCM), and then in this tissue, we select those immune cells that are known to be present, and we modulate this immune tolerance that we mentioned before. Then we check if some of the more aggressive cells are overrepresented, some of the supportive cells are underrepresented and find out what is wrong in these balance of forces and this can be done with IMap testing. Then also we can apply conclusions of the immune-modulatory drugs for very specific constellations of these imbalances. There is another aspect which is also interesting in egg donation cases. You have to understand that an embryo in nature is half of the genetic load that comes from the egg. As long as it is a homologous treatment, this half of the genetic load of the embryo belongs to the mother which we call hemi-allogeneic. The father is always a foreign person in terms of immunology, but the embryo is only hemi-allogeneic. In terms of egg donation, the genetic load of the father is foreign as the genetic load of the donor which means this is a complete allogeneic structure which, we know that helps the implantation because then the immune system and the immune tolerance works better. This is why a cycle of egg donation would have a little bit better success in another woman then if these embryos are transferred to the same donor. This is something very interesting to know, so nature supports diversity. The egg donation process is nothing anti-natural, it even gets recognized in the way that success is a little bit better. But as both parts of the genetic load of the embryo are foreign, some groups of proteins belong to the histocompatibility complex or HLA antigens, that define our immunologic singularity that maybe are not right-aligned. This generates f. e. that some cells create KIR mediators, these are molecules that can activate very aggressive immune cells and, in the end, we have histocompatibility complex molecules, so we have a higher risk of implantation failure in those women. This is something we can correct nowadays, testing for the KIR and HLA of the woman, of the husband and the donor this is what we call immunologic matching, and then we can decrease this risk, we cannot make it disappear, but we can decrease this extra risk of the allogeneic situation to the normal risk of the hemi allogeneic situation and the immunologic rejection can be set back to the levels of normal spontaneous pregnancy.

Endometritis is underestimated. There have been studies, at the end of the 90s, big studies that were driven from Switzerland. In thousands of patients, it was shown that when it comes to implantation failure up to 10% to 15% of those patients had some kind of non-physiological microbiological agent inside the uterus. Most of the infections of the uterus are acute and can be treated and will disappear, but some of them get chronic, and this is a problem. One of the clinical signs for that, related to no pain, is also a thin endometrium, so this inflamed and infected tissue does not react properly to the hormones. It’s not growing properly and, at least at that point or even better for everybody that gets a biopsy of the endometrium, it should be tested if there are signs of endometritis, there is a way to do that. There are two steps, first, you have to culture the biopsy in the normal culture media, this takes a couple of days until some colonies of certain pathogens may grow and then you can detect them, and you can test them with antibiotics, and have the complete antibiogram which drug will help to eliminate them. More than half of the chronic infections are due to another kind of parasites that do not grow under normal cultural conditions because they live inside the cells, and therefore you need anatomic pathologies that will take a look to this tissue and evaluate if there are so-called plasma cellular complex cells. These are cells inside the tissue that recognize that the material cells are infected intracellularly through pathogens like ureaplasma and mycoplasma and others that do not show up in a culture and, therefore there is also specific antibiotic prophylaxis. You would need to take that for a couple of weeks, and then the problem is over. This is a quite underestimated risk that is not checked in most clinics.

Well, yes and no. I have mentioned before, endometritis is associated with thin endometrium, and impaired blood flow is also related to implantation failure, and also to a thin endometrium. The endometrium will grow as long as hormonal triggers can arrive. If there is a restricted blood supply, then it will not grow properly, but in the end, it is not the thickness of the endometrium that makes the difference. The thickness of the endometrium is just a symptom. Big studies on thousands of patients were done, where the physicians tried to correlate the thickness of the endometrium to the success of the transfer, they did not show anything. They couldn’t correlate these two parameters credibly, so it is not the thickness of the endometrium, you can find pregnancies in the endometrium that is 5 millimetres, you can find those also in the endometrium that is 15 millimetres. The optimum is not related to the thickness. Very low endometrium could be related to Asherman, chronic infections, and things like that, you have to solve before. Very thick endometrium could be related to hyperplasia or even to cancer which you also have to clear before. But in the normal range, it is unrelated if the endometrium is 7 or 14 millimetres, it’s really irrelevant. What really makes the difference, is the blood flow. Subendometrial, this means beyond the endometrium, is something that we can measure with special ultrasounds, and the parameter with the highest correlation to pregnancy success is the so-called vascularization flow index (VFI), to measure that you need a three-dimensional power Doppler which measures the density and blood flow of small vessels in a certain volume of the endometrium. If this value is below a certain level then, the correlation with implantation failure is extreme. How can you correct that? First, by eliminating infections, Asherman’s and other problems. Are there drugs that could increase the blood flow inside the uterus? Yes, there are that are used in cardiovascular medicine for decades, so there is also viagra and other drugs that have shown to increase a little bit this flow. There are also other attempts with regenerative medicine, installation of growth factors behind the uterus, the endometrium that would increase this blood flow. In conclusion, thin endometrium is only a symptom, it’s not the reason for lower implantation. Knowing this and fixing the blood flow, there are also ways to improve the blood flow, then the endometrium thickness would improve and restore the implantation potential.

The indications are recurrent implantation failure, and like I’ve mentioned before, Asherman syndrome, this is an endometrium which lost the capability of regenerating new cell layers, and these are the original indications. We have worked with such indications restoring the capability of getting pregnant of Asherman patients, in a way that they could achieve 80% of pregnancy rates after that treatment, the potential of the regenerative medicine on the endometrium is amazing. We started with those very difficult cases where patients were close to going to surrogacy because it was impossible to create a suitable endometrium. Then the regenerative medicine showed that it can restore, in most cases, normality which is amazing news. But later, we have included other indications that could profit from this approach. This is the low blood supply as I’ve mentioned before, and also immunologic dispenses. Perhaps, the same happens also for hormonal displacements because there is an endocrine, this means hormones of the patients affect a certain tissue. There is also a paracrine, this means cells of surrounding also affect glands and tissues for the embryo receptivity. When we transfer a needle concentration of own blood to the subendometrium, what kind of display of all these affects increasing blood flow, modulating immunology and increasing the paracrine growth adaptation, this is still under investigation. The fact is, that it seems to work. So the indications now are only chronic infections and Asherman, but we are expanding them to immunologic implantation failure, and we think this is the future.

Two or more failed transfers of good quality embryos. I suppose in an egg donation treatment that the embryos were of good quality, so by definition, this patient is, unfortunately, in the group of implantation failures. You should first look for the possible reasons, you should do the endometrial biopsy with a receptivity testing, endometrial biopsy with immunological testing and with chronic endometritis testing. The good news is, you can do all three in one step, but first I would try to diagnose if the failure is in the implantation window if it is in chronic infection or if the failure is in the immunologic imbalance. All three issues have different approaches, and once this is cleared, you can try again, and this will work.

Hashimoto and some autoimmune disease. Two main antibodies are created by the immune system against the own thyroid glands and by the way they also attack the endometrial tissues so that the implantation is heavily impaired. So far, monoclonal antibodies are not ready, could block this specific interaction, the only way we know to counteract these high levels of anti-TPO, and anti-TG is prednisolone. High doses of prednisolone, in a way that you could get adverse effects from that but it is the only way to keep the risk of implantation failure, and the higher risk of miscarriage rate as low as possible. Other methods to avoid implantation, there is no evidence and no clinical study to my knowledge right now if regenerative medicine could help to improve that situation, specifically in the endometrium. From the intellectual point of view, it could be reasonable, but there is no clinical experience with that.

So if this is the case and we are talking about IVF with own eggs then I have to come back to my first sentence, where I said 80% of the implantation, also of the capability of maintaining a pregnancy depends on the embryo quality. The embryo quality depends on the egg quality, in terms of maternal age. At 39 or 40, we know that the percentage of the blastocyst, not of embryos, it would be even higher., so blastocyst that has wrong chromosomic formula is between 70% to 80%. So the most probable explanation for this patient is that this embryo was aneuploid as such embryos do not implant, even if they implant, they stop growing very early. And the answer to the last part of the questions is absolutely, not. Freezing of embryos is a technology that is known for 20 years. It has got improved, during the last, decades in a way that frozen embryos are not even weaker than fresh embryos, and now I will say something shocking, maybe they behave stronger than fresh embryos. We don’t know why, but if you compare fresh transfers with frozen transfers in substituted cycles, there is no measurable benefit of transferring the embryos in a fresh cycle. There is even a slight improvement of the implantation if they are transferred frozen. Taking into account that everything went fine and there was no accident in freezing or defrosting of that embryo. If current technology with current reliability and accuracy could be applied, then there is no damage to the embryo, and maybe the improvement is very small, it’s not statistically so significant, and we are not sure it would get confirmed in higher series. One of the possible explanations for that is that the freezing process puts nearly 200 cells of an embryo under shock, and then the clock of the growth, of the cell division patterns which is called the cell cycle, gets aligned, and in the end, when they arrive for the transfer and have to start this dialogue with the endometrium, more cells are giving out these triggering signals, at the same time as in the fresh cycle. I can only remark there is no damage to vitrified blastocyst.

Yes, to the last question for sure because it would be like an essay that compares only one differing parameter. If all the rest of the parameters were the same so same cycle, the same eggs, the same woman, the same lab, and the same retrieval and you only exchange the one factor which is the sperm, then you would see the differences very clearly that are applied by those factors. Having said that, 59 years of age of your husband is more related to epigenetic activation failures of the embryos than the appearance of the blastocyst. They are related to the blastocyst rate more than in the first three days of development because, in the first three days, everything that happens is driven by the egg, after that, we call it zygotic activation, then the embryo has to read their own genes and activate their own replication machinery autonomously, and then obviously the father counts. Before it didn’t count, just for the fertilization and nothing else. The blastocyst rate where the impact of the male sperm is evident could be checked in a way like you proposed comparing it with the same court of embryos with another sperm. If you can’t do that because you will not have so many eggs probably to waste them in this way, and possibly your husband is still interested in having his sperm being used. I would recommend to you is to do PGS with your husband’s sperm, in a way that you could accumulate as many embryos as needed until some of them can be detected as being genetically normal. Then, also take care of the implantation window and then other possible implantation failure sources because these 2 embryos that you could generate in the next months, they are like gold. You should not transfer them before knowing what is exactly happening with the endometrium. Going for that reason now for sperm donation is something I would not recommend.

This is extremely linked with each other. Preeclampsia happens 2 to 3 times more often in egg donation cases, and there are there was a lot of debate why. This has to do with the hemi-allogenic embryo, and allogenic embryo behaves differently because they trigger different responses of the immune environment. They open a different immune tolerance pathway which allows the embryos to go a little bit deeper and to attach to the lower levels of the placenta, in a way, that the blood supply is different, in a way that there could be some restrictions for once the placenta grows for providing enough blood flow and this is one of the reasons for the preeclampsia. If the fetus does not get enough nutrients, the way to compensate that is increasing the blood pressure of the mother. Once these vessels are under such big high pressure, the time comes where they are insufficient, they cannot supply enough, and this is why preeclampsia leads to premature deliveries, and this is a risk associated with the immunological response in the very early stages of implantation. This happens during the first 3,4 days of implantation and this is why, some think of using regenerative medicine or this immune modulation, or this immunological resetting of the endometrium to allow this not to be so prevalent. Another issue is also the kill HLA analogy, so the genetic matching in cases of egg donation. We expect that aligning the HLA typology of the donor to that of the mother, then the implantation will happen as in a Hemi allogenic way, and then the depth of implantation will not be the same. Hopefully, this will then eliminate the higher risk for preeclampsia, that egg donation patients have. There is no test, the only one I would say is the genetic matching, so if we are talking about the egg donation cycle, then genetic matching would help to present that. Then there are also immune-modulatory drugs that could help to make this impact a little bit weaker. I think that has been tried with corticoids, but it’s very difficult to measure that. Test to diagnose that in advance is, unfortunately, not available. In a biopsy for the receptivity testing, we can theoretically also address some of the mechanisms in the blood flow formation and so on, that could contribute to the preeclampsia, we could just define if the patient Has a higher risk, but this will not help us in influencing that risk. It is known that some patients have a congenital higher risk for preeclampsia because some of these mechanisms are also impaired, this is something which is inborn, and this will get repeated every time.

The chance is low with egg donation. From 12 eggs, imagine 10 can be fertilized and then from the fertilized, the blastocyst rate is 40% to 60%, possibly 5 blastocysts could be created from that. From that, if you can assume the risk that at least one of them will be genetically abnormal if you are a Little bit unlucky it could be 2 or 5, which is then substantially more. If you can live with the situation that the most probable scenario is that the healthy ones will implant, and the unhealthy ones will even not implant. If you can live with the possible failed transfer which can happen, also for many other reasons, then this is not justified to analyze that. If you take into account what we mentioned before, the costs of the PGS and the cost of the cryo transfers and the lost time and so on, it could be a financial decision and, also for your peace of mind. If you work with your own eggs and you only get maximum 5 eggs, I suppose you’re between 37 -39 or even more, so if you are already at that age group, then PGS testing is mandatory, in my opinion.

If the receptivity is proven, if you have PGS tested embryos then you have covered more than 80% of most popular implantation failure reasons. What still is not being studied is the immunology. So if this is a treatment with your own eggs, you don’t need to check for the KIR – HLA or perhaps, the KIR- HLA of your husband. Performing a biopsy of your endometrium and evaluating the balance of forces between aggressive and non-aggressive cells could be a key for that because obviously something serious is happening behind that. 3 IVF pregnancies with miscarriage are also an indication of some kind of immunological problem and having 2 PGS tested embryos are quite evident that there is something behind receptivity and behind genetics. This could be something anatomical, I would recommend doing a hysteroscopy to check that you don’t have any blood supply deficiencies. I would recommend doing three-dimensional power Doppler examination to check the flow index of your sub endometrial vessels, and they would check in your situation also the immunology and the chronic infections before going for the next transfer.

It is a bit like the last patient because the genetic reason for implantation failure explains the 9 own IVF cycles between 39 and 45. Having opened the new era of egg donation, six good quality embryos were 2 have been transferred with receptivity tests, hysteroscopy and so on. What I’m missing here again, is the immunology. Was your donor matched genetically in terms of HLA and KIR? Have you done the immunologic mapping of your endometrium? Have you used any kind of a new modulation before and I would start with that and if still all the other 4 embryos do not implant or get implanted and miscarry, then maybe you have a more paracrine problem which could be related to age also so these regenerative medicine approach or rejuvenation of the tissues resetting of all the stem cells and of all the growth factors maybe could be helpful for you too. But having had only two embryos transferred after receptivity tests. Without immunological testing, I would first start with immunological testing, immunological modulatory therapy, try the 4 embryos that you still have and hope that 1 of them will succeed and if not, then go for regenerative medicine. As I’ve mentioned before, what the sperm contributes to the embryo quality is very small. What you could do is perform PGS on those 4 frozen embryos and don’t be afraid, usually, it’s possible to defreeze them, take a biopsy and freeze them again. Embryos do not suffer from freezing and defrosting if it’s less than 20 times, and it will only be two times. Then you would know more about the genetics of the embryo and if despite using donor eggs you can detect certain chromosomic abnormalities in those embryos f. e in sexual chromosomes that are usually very linked to sperm. Then you would have a reason to believe that there is something wrong with the sperm, but as long as your husband is health, he has a normal DNA fragmentation, he has a normal sperm count, the reason will rely much more on the quality of the eggs.

Recommendations are up to the 12th week which is already a quite big security zone. The implantation starts the presentation quite early, and the hormonal supply that you need to take in a substituted cycle usually, are generated by the luteal body. In this case, if you don’t have ovulation, you don’t have a luteal body, and you have to substitute them. There is a lot of evidence that the early placenta from the 10th week of pregnancy can already create all the hormones autonomously that the later pregnancy needs. So if we give 2 additional weeks of external hormones, this is what I mean with security area. You can stop in all cases the supplementation of the substitution of those hormones beyond the 12th week of pregnancy. You don’t need to keep this until the 4th month of pregnancy, this makes absolutely no sense. So if there is something wrong with the placenta, that it is not able to create these hormones by itself, there is something so physically wrong with the placenta that it possibly will not sustain the whole pregnancy very long. This is quite unusual because all miscarriages happen before the 12th week of pregnancy, after that if this placenta empowerment has happened, there are as good as no miscarriages any longer. Maybe there are infections or premature intrauterine deaths or other complications of the second part of the pregnancy, but miscarriages are very rare.

It is a pretty much fixed, but because this is like an individual fingerprint, it can change. What we have measured is that after operations of the uterus, after removing the whole endometrium f.e. after an abortion or an infection or delivery with a placenta attached to the uterus, you have to aggressively remove this residua tissues, this may change after that, and it may change also after deliveries. This is why we only perform a secondo receptivity test if in the time between, there was an event like delivery o surgery or other causes.

So, it matters a lot. It’s not only about time but also about the bioavailability of the drugs. When doing a transfer, we always perform also a serum level of progesterone because of the same dose of usually vaginal pessaries of micronized progesterone that has to go inside small fat balls into the blood and so on. So the biokinetics, and the pharmacokinetics, as well as the bioavailability of the drugs, may change a lot between patients. Once you have defined your window of implantation to a certain time and with a certain dose, then you should not leave this scheme because changing times or doses may change everything. This is why it is better to perform a progesterone level in blood under the standard progesterone level during the time of the receptivity testing to know if the bioavailability of this drug is normal in your case, or not. If you need to increase the doses to at least 9 to 12 picogram per millilitre of progesterone in your blood to the time of the transfer, then you should know this before making conclusions from the receptivity test.

It’s not delaying the IVF, it’s the opposite. Biopsy of the endometrium is very easy, you can perform that without any sedation, this is something that you can perform in a normal consultation room. It’s not comfortable, but it’s not painful. Once you have scratched the endometrium a bit, maybe you have heard also about the scratching procedures or that women tend to get pregnant more after an abrasion or after manipulation of the uterus, or even after hysteroscopy and this effect lasts only for 2 to 3 months. The explanation for that is that the manipulation of the inner part of the uterus creates a kind of local inflammation that helps to align the immunologic and the paracrine waste properly. The operated uterus is more suitable to get pregnant in the next cycle as, without manipulation. This is something you can read in the medical history books and the same effect you could profit from the biopsy because the biopsy is irritation, and it provokes an inflammation which has a positive effect on the implantation. After, the biopsy of the endometrium, go ahead with the IVF as soon as possible.