Implantation failure is determined when embryos of good quality fail to implant. This can happen for different reasons, including embryonic, uterine, endometrial and tubal causes. Successful implantation needs specific “cross-talk” between a good embryo, a receptive endometrium and a functional uterus. In fact, the latter, being the “natural incubator”, is the most forgotten cause of failures in IVF treatments, being it either with own or donor eggs.
During this live webinar, Dr Nadia Caroppo, the Head of the International Medical Team at Equipo Juana Crespo, revealed what factors enable successful embryo implantation followed by a clinical pregnancy.
Reproduction itself is like an orchestra. If the latter does not sound good, it is because one or a few of the instruments are failing. The same with human fertility. Dr Caroppo admits that it is one of the most complex issues in the field of medicine. Mainly, because there are so many variables that should be handled to assure the final success. However, a lot of things in reproduction are still unknown. Dr Caroppo quotes her boss and mentor, Dr Juana Crespo Simó, who even claims that an implantation failure as itself does not exist. It should be rather perceived in terms of several problems that doctors sometimes just do not know how to diagnose.
There are several definitions of ‘implantation failure’, depending mostly on the fertility society forming it. Generally, it is understood as the impossibility to obtain a clinical pregnancy with the transfer of at least 4 good quality embryos during at least 3 cycles in women under the age of 40. However, the criteria is not strict and it depends mainly on a patient’s individual case and the cycles she has had before.
Dr Caroppo says medicine should always be personalised. It is necessary to adapt medical treatment to individual characteristics and the history of each patient. The correct diagnosis is the first step towards the correct treatment – meaning the right plan and strategy for a patient. It also refers to the embryo transfer itself.
The gold standard for reproduction is natural conception. According to the study conducted on 1,000 postpartum women, the conception period for natural pregnancies is 3 months in the case of 65% of women. The rest have to wait for a successful outcome for up to 18 months. In comparison, 65% of egg donation patients need to have 5 embryos transferred to achieve a live birth. According to Dr Caroppo, these results demonstrate that the implantation success is not the result of good quality eggs and embryos. There are other factors affecting the process – both in case of own and donated eggs.
There is one thing that all conceptions (both natural and through IVF) have in common – and this is a woman’s uterus. Dr Caroppo compares it to the most important incubator – however, it is also, the most forgotten one.
Embryo implantation is not a passive process. The endometrium and the embryo exchange messages have a kind of a ‘cross-talk’ between each other. It has been proved that a good quality embryo is able to positively change the environment inside the uterus. In the same way, it seems that even a poor quality embryo can improve its performance if the uterus and the endometrial lining are functioning correctly. Women with hyper-fertile uteruses get easily pregnant with any type of an embryo – either normal or abnormal. Of course, the latter generally results in a miscarriage.
According to Dr Caroppo, these are the ‘easy patients’. In their case, the treatment protocols require to adjust only one factor, namely the embryonic one. At the opposite end, there are patients with the hostile uteruses, characterised by very poor receptivity. Such uteruses will always fail, no matter how good embryos they receive. These are the most difficult cases (called ‘low responders’) that have to be treated in a very specific way. However, it has to be highlighted that woman’s age makes a significant difference here. If a ‘low responder’ patient is very young, her chances of getting pregnant are much higher as the quality of her eggs is much better.
Dr Caroppo says there is always a certain percentage of patients who have to undergo preimplantation genetics testing (PGT / PGS) for abnormal embryos. This includes women who need to have chromosomal problems ruled out for the implantation failure. Dr Caroppo presents the results from the Equipo Juana Crespo clinic showing that, in case of PGT-tested embryos, clinical pregnancy rates increase a lot – up to 70.6% in cycles with own oocytes and to 75% in cycles with egg donation.
Using PGT – PGS – genetic embryo diagnosis clinical pregnancy rates increase a lot – up to 70.6% in cycles with own oocytes and to 75% in cycles with egg donation
This is another reason that accounts for the personalisation of reproduction medicine. In Dr Caroppo’s clinic, doctors usually suggest PGT to women who are 42 years old or above, just to assure they have got normal embryos. However, around 90% of all the clinic’s patients suffer from endometriosis. So even if PGS testing is indicated, it has to be remembered that the embryos belonging to endometriotic patients will suffer a lot when taken up to the blastocyst stage and tested. Dr Caroppo says that in such cases, the doctors’ main task is to provide those embryos with the best opportunity to implant. To do so, they have to place them in the correctly treated and well-conditioned uterus.
Having assessed each case individually and ruled out other causes (e.g. thrombophilia or blocked fallopian tubes), doctors can focus on the uterus. They have to study not only its anatomy but also functionality. Dr Caroppo differentiates two types of tests conducted on the uterus: morphological and functional ones. The former includes 2D and 3D ultrasounds and pelvic MRI that are used to rule out pathologies that are not easily seen. The uterus functionality is, on the other hand, assessed by using hysteroscopy (to rule out endometritis, adenomyosis or fibrosis), subendometrial Doppler (to see vascularisation in the sub-endometrium) and contractility tests (made with video MRI to assess peristalsis).
According to Dr Caroppo, the most important part of the uterus to assess is the fundal one. It is the functional part and it is where embryos attach. As the uterus is a functional and hormonal dependent muscle, its changes depend on multiple factors – both acquired and congenital. These factors include painful periods throughout a woman’s life, altered menstruation patterns, previous C-sections, long labours or myomectomies – in other words, anything that can harm the inner muscle walls and change the uterus functionality. Fortunately, most of these changes can be repaired to restore the uterus functionality. It is an important fact to consider when ruling out factors that affect implantation.
Choosing the treatment
According to Dr Caroppo, making the diagnosis is the easiest part. However, it is useless if you do not know how to treat different types of uteruses. Fortunately, doctors have many treatment options available, including medical and surgical ones. First, there are a lot of medications that can be used before proceeding with surgical treatment, such as e.g. anti-estrogens, progestogens, dopaminergic agonists, corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs) and antibiotics.
When it comes to surgery, the most important treatment is laparotomy. However, it is best avoided and used only when it is highly needed, assuming that other techniques have failed. Dr Caroppo mentions that open laparotomy may in some cases result in some of the most serious pregnancy complications following surgical treatment, such as uterine ruptures, premature births or an intrauterine restrain of fetal growth. This is why Dr. Caroppo Caroppo’s principal advice for all fertility patients who are to undergo any type of surgery is look for an experienced and trained reproductive surgeon. Only such specialists know exactly what should be restored in each case to give the uterus its functionality back.
Making it work
Although the range of treatment possibilities are wide, Dr Caroppo reminds us that doctors do not use all of them in each case. The choice of treatment depends on the type pathology that is observed, the strategy that should be adopted and – most importantly – on the patient’s past failures and medical history. The main endpoint of all these efforts – apart from getting a patient pregnant – is making her uterus work. However, there are no secrets to the final success. It is always the result of thorough preparation, hard work and learning from failures.
First of all, if you have sensations and painful periods, just go to your gynecologist and get a checkup to see if there’s no endometriosis or signs of adenomyosis. Even if adenomyosis is in very early stages, it is very difficult to diagnose. Basically, conduct a healthy lifestyle. A healthy diet always helps us to improve the condition of the uterus – especially Mediterranean diets have proven to be very effective in that. Remember that if you leave the problem (such as e.g. painful periods) to evolve in the future and you do not take care of what seems not to be normal, you can have a uterine problem if you get older and you want to get pregnant. So just try to take care of yourself and your uterus. If you have endometriosis, getting on the pill or using Mirena (IUD) can help to prevent and protect the uterus.
Everything depends on the blastocysts’ quality. There is the question if the embryos were ok. And besides, your ovarian reserve is very low. So we have to rule out the possibility that those embryos were not healthy – the first thing is to test embryos. Secondly, it is important to understand how they transferred the embryos. Was the transfer painful, did you bleed, what uterine preparation did you have? Was it a fresh transfer or not? How much estrogen was given to you? I don’t know if with 43 years old, you would have any good embryos left. We don’t have any markers to know if you have healthy eggs left in your ovaries or not. So if you have good blastocysts arrival – even if you have a low ovarian reserve – I consider that we have to test for those embryos first. And afterward, it is recommended to study your uterus a little bit more and understand where the preparation failed in terms of your transfers. I think that is one of the most important points for you and your physician to consider.
It’s a technical denomination. PGT means ‘preimplantation genetic testing.’ You have testing for chromosomally abnormal or normal embryos and you have molecular testing for those couples who have any hereditary disease that has to be ruled out in embryos. The slides that I showed you are from PGT (pre-implantation genetic testing) for chromosomally abnormal embryos. You will find it also as with other names.
In our clinic, we don’t believe in guaranteeing eggs. It all depends on what we need. Generally, for our donations the range is between 10 to 13 eggs, depending also on the donor. For each donation, we expect to have 2 embryos per transfer. However, in most cases, we tend to freeze from 2 to 4 embryos – not counting the ones that are transferred. We tend to synchronise the patients with the donors just to perform a fresh embryo transfer so we do not always freeze all the embryos.
It’s a very good question. We do not believe a lot in the ERA test because we are running some protocols where we see that it’s not a problem of receptivity itself. It’s just opening the window of implantation by ourselves. The ERA test is not the final word on implantation failure – it is only an instrument that can be used. We see lots of patients that have performed ERA, ALICE and EMMA tests and did not get pregnant, even with respecting the number of hours recommended by the ERA test on whether it was receptive, pre-receptive or post-receptive endometrium. Of course, if we have that information, we can use it. But we usually do not perform it ourselves in the clinic because we see that it’s not a thing of receptivity. It’s opening the real window of receptivity by ourselves. Especially in natural cycles, we tend to use some very new protocols where we open the window of implantation by ourselves. We are just gathering information and we have very good data now, the numbers are very good. So it’s something that can be done, it’s something that may give us more information. But having defined the uterine problem first, we can perfectly settle with an ultrasound and a consultation hysteroscopy showing which endometrium will give you a correct pregnancy and which one won’t. So I’m not very fond of the ERA test. That’s my opinion. I don’t consider it a must. It’s not the principal factor for me.
No, we do not perform hysteroscopy each time. We perform a consultation hysteroscopy when patients have failed lots of times in other clinics or have failed any embryo transfers with us – just to rule out that there’s no pathology in the endometrial lining that can justify that negative result. If you mean a surgical hysteroscopy, then as I told you: 90 % of our patients have autonomy adenomyosis that is an under-diagnosed uterine cause of implantation failure. Sometimes we just need to take away the scar tissue that is formed inside the uterus, re-modulate the cavity and try to get back the tenderness that the uterus had in the past and restore the functionality – sometimes all of that with a hysteroscopy. It depends on each case and it’s not something that we do 100% on all of our patients. And we use a consultation hysteroscopy to see the endometrial pattern. We usually do it when there is a negative result or when we suspect that the endometrium is a problem – whether it’s being chronic endometritis or endometritis because of altered flora.
There are some supplements that we tend to give, especially vitamin A and E for a short period of time. They do not improve the uterus quality but the quality of the endometrial and sub-endometrial areas. They do not have to be administered for a long period of time – we just administer them for a short period of time and depending on each case. So yes, it’s something that can be done. We give them but we just stop them if a patient gets pregnant or we stop them before they get pregnant if they have been treated for the timing we consider best. Other conceiving supplements are folic acid and vitamin B. They’re general supplements that do not improve the uterus quality a lot, they are just supplements for the embryo. But as I told you before, there are some vitamins like A, E, and D2 that can improve the quality of your endometrial lining and the sub-endometrium healing a little bit.
It’s a good question. Sometimes the success does not depend only on the day the testing was done, it depends also on the quality the embryo has. Sometimes an intermediate or low-quality embryo, which is normal, is not thawed properly. So even a normal embryo cannot get you pregnant. We use agonists a lot. Sometimes we give the agonist for one, two or three months, depending on each case. So yes, it may be a good strategy but we also have to monitor the estrogen levels. Very high estrogen dosages for a long time may alter uterine receptivity or uterine functionality. As I told you before, the uterus is a hormonal dependent organ. If we suffer from, for example, adenomyosis (that is a hormonal dependent pathology), we may be making it flourish by doing so – even though we put it at rest with the agonist. So yes, it’s a good strategy, if they have used other protocols. I think that it may be a good thing to use if it’s your last embryo. But keep in mind that a normal embryo may not implant either – just because it belongs to a 42-year-old woman and maybe its quality was not top. And that can alter the thawing process.
It’s a tricky question. The chances of getting twins with the egg donation program, if you transfer two embryos, are high. But nonetheless, the most important thing is also to assess which type of patient we have in front of us. 49-year old patients tend to have very high-risk pregnancies because of preeclampsia, pre-term birth and gestational diabetes. If you add that to the fact that twin pregnancies also increase those prenatal problems, my advice is not to transfer two embryos but just to transfer one embryo. If you have good embryos from a double donation (being sperm and egg donor) and the uterus is well-conditioned, it is very risky to transfer two embryos. My advice is just to transfer one embryo.
Biochemical pregnancies tell us about a uterine problem, not an endometrial problem. Those are embryos which stick to the endometrial lining but – for some reasons- they’re not able to carve into the uterus and implant. There are two ways of implantation: the first one is when you get your HCG test positive and the second one, around 6th to 7th week, where the embryo just scratches more deeply into the uterine muscle. You are 34, you are very young, and if you have normal embryos and you do not get pregnant, the problem is somewhere else. I don’t know if they have tested your fallopian tubes but that is very important to start with. And, secondly, to get a good diagnosis of your uterus. Normal embryos shouldn’t have any problems with implanting. They have the implementation rate of 75 % more or less. So my advice for you is to get tested for pelvic MRI in the luteal phase, being the phase after you ovulate. You should see a physician who understands everything about pelvic MRI, get a good scan and have some feedback on your uterus. Being 34 years old, you got a biochemical pregnancy with IUI and now you have undergone three IVFs with normal embryos. Even if you have low quantity of eggs, you are capable of giving us good embryos. So I believe that the problem may come from the uterus or your fallopian tubes. I don’t believe it’s a an endometrial problem because with IUI, you got a biochemical pregnancy. That’s something that should be studied a little bit more deeply. It’s better for you to do a consultation and just rule out uterine factors. That’s my advice.
Uterine fibroids, or myomas, can be the cause of a miscarriage because they alter the contractility. Even if there are myomas that are intramyometrial, in the thickness of the muscle, the more myomas we have, the less receptive the uterus is. And they can lead to miscarriages. In recent studies and at the recent congress dr. Crespo went to talk, it was discussed that myomas have to be treated – even the ones that are very little. Above all, the ones that are placed near the subendometrium, the parts just lining with the endometrium, and the ones that are intramural. The ones that are subserous – in the outer part of the uterus – do not account for miscarriages. But it’s true that lots of myomas may be the cause of a miscarriage. So that also has to be assessed. My advice is also to have pelvic MRI to see where the myomas are and if they have to be operated on, not just an ultrasound. I think that if you got pregnant with egg donation and you miscarried the baby, the baby probably would have been chromosomally normal. So it’s very important to rule out the uterine problems before you undergo another egg donation or another embryo transfer if you have any embryos left. That’s my advice to you.
Nowadays we tend to implant just one embryo. But it’s true that sometimes we have very difficult uteruses that need more than one embryo to get pregnant – with one baby, not twins! So it depends on the type of patients, the type of uterus, the treatment with that uterus and the quality of the embryos we have left – even if they are normal healthy embryos. Today almost all clinics tend to do a single embryo transfer of normal embryos. But in our experience, we see that there are lots of patients who need two embryos to get pregnant with one baby because they have very difficult uteruses. Here in Spain, by law, you cannot transfer more than three embryos. We transfer three embryos very rarely and it happens to the least of our patients. We have to consider embryo quality, uterus functionality and the difficulty we had to prepare that uterus. So it depends on each patient but generally, it is one or two embryos – not more than that. If it’s two embryos, then it’s not with the aim of having twins. Sometimes it’s only with the aim of getting pregnant with one baby.
There’s no time frame between cycles. It depends on the time frame of each patient, the uterine preparation that we have to do and the endometrial preparation, too. We try to synchronise most of our patients so the time frame is very short. The search for a donor is done in more or less one month. Once we have the donor, we communicate it to the patient and according to the preparation we will need to do, we will settle the date just to synchronise the donor stimulation and the pick up with the fresh embryo transfer. But you don’t have to wait for any particular time between 2 IVFs. It depends on what we have to do next or on the strategy for you to get a transfer.
Yes, there are lots of things that are being tested right now. The new thing that they are talking about is the normal flora inside the uterus. What is the normal flora? What is the pathogenic flora?What will give you a correct pregnancy – a receptivity test or other biochemical markers that can identify a good pattern of implantation? There are chronic endometritis markers – they’re called proteomics. There are lots of things that we don’t know, even if they are in the research field. You may also have heard about immunology: KIR receptors and HLA-C receptors. They’re called the compatibility test. Up to now, American, Spanish and European societies in the immunological field of reproductive technologies have not recommended to attend to immunologists because there’s no consensus and no definite treatments to increase the implantation rate. We are collecting data of all patients who went to an immunologist and were set up with Heparin, Aspirin corticosteroids, etc. but got pregnant without following those recommendations. We are conducting a study right now that makes us open another field for the window of implantation – namely: how can we manage to open the implantation window by ourselves, regardless of the timing of the ovulation? That is a new thing that is being done. Unfortunately, fertility and reproduction is not exact science. Even we ourselves commit a lot of errors. Why? We think that some patients and couples won’t get pregnant and they do get pregnant. Sometimes we just look at ourselves and ask ourselves: what did we miss? We thought this was impossible and they got pregnant – what did we believe before and what did we do to get them pregnant? So there are lots of things that are unknown. There are lots of studies that are being conducted right now. For example, non-invasive embryo testing without performing the biopsy but with just taking the liquid out of the culture media they are in and assessing the proteomics and the genetic factors that can let us see the normal results of the embryos and the proteomics of that embryo – some molecules that tell us if the embryo will implant or not. So there are a lot of things that are now in study but they are not recommended as regular treatments to our patients. In the future, I think we will have other things that can tell us how to diminish the implantation failure. There’s of course a percentage of patients who will unfortunately fail, regardless the uterine factor or the endometrial factor or whatever else. So yes, there are lots of things and I hope we can learn more in the following years.
Yes, there’s a possibility to do an online consultation. You can get to know our clinic on our website, you will find our contacts there. We will arrange Skype visits for you. We will ask you to send us all the information on past protocols you did (IVF protocols, donor cycles, blood work, etc.) that can help us to study you a little bit more and comprehend what happened and what might have failed for you. The online consultation lasts for around one hour or one hour and a half. You will find there me and a nurse and we will also give you some feedback on what we would have to do next, including all the things that you will have to do in your country. Eventually, we can arrange an inpatient consultation whenever you want and arrange for the tests, if you are not able to do them in your country of origin. We can arrange to do those tests in one day with the hospital we work with. Pelvic MRI and hysterosonography are not tests that we can do in our clinic. However, we can do blood work in our clinic, we have a lot of facilities and you will be followed by one person throughout the whole process, whatever type of treatment you have to undergo. So yes, it’s absolutely possible.
There are two types of DNA fragmentation: single-strand and double-strand. There are some tests to be done that can rule it out. Sperm fragmentation may give you lower quality embryos, the so-called more fragmented embryos. It’s true that there are some papers which account that there is a higher risk of miscarriages with abnormal DNA fragmentation. But it’s true that if you undergo, for example, ICSI (intracytoplasmic sperm injection), single-stranded DNA fragmentation is ruled out. There are other mechanisms to rule DNA fragmentation out, like Fertile Chip, where we tend to choose sperms that are not fragmented. But using those tests means that the sperm count has to be normal. We do not have many male factors and even if we have high percentages of DNA fragmentation, we just treat them by doing the gradients to rule out single-strand DNA fragmentation. We do not believe a lot in that. It’s because we had several patients who had high DNA fragmentation, we made IVF cycles both with fertile chip and without fertile chip, and the results were exactly the same. So we are not keen on that. Of course, we have those methods in our clinic because some patients require them. We have a very good lab, very good biologists and andrologists who take care of those things and they are very good at choosing sperms.
Basically, it’s not only a problem of quantity but it’s a problem of location. Fundal myomas are a big problem because they occupy the space that has to be occupied by an embryo. Generally, when we have intramyometrial myomas, and they’re big enough (2-3 centimetres), we tend to operate on them. But the first thing we have to rule out is where they are placed. So if I have a single fibroid that presses onto the cavity, but it’s not inside the cavity, we have to take it out, even if it’s a single one. If you have a whole lot of myomas, we, of course, have to take them out – just to restore the functional fundal part of the uterus and restore the normality. Maybe we won’t take away other myomas that cannot be reached – because they’re in the lower part of the cavity. But those myomas are not a problem. The ones that are the problem are those in the fundal part of the uterus. So it’s not just a question of a number but it’s a question of where they are located.
Yes, it can be diagnosed by laparoscopy. Generally, adenomyosis gives you a big uterus. The first suspicion that you may have adenomyosis comes with a histological sample taken during a hysterectomy. When we take away the uterus, the pathologist will tell us if there’s adenomyosis. But that’s not the gold standard for us of course because we treat patients who want to get pregnant. We have very good means to diagnose adenomyosis with an ultrasound, pelvic MRI and eventually hysteroscopy. Some adenomyotic caverns are just underneath the endometrial lining and we can see them. We see black marks and black spots and when we open them, we see blood coming out of them. Or we see caves that are the scarring process of adenomyosis. So you can have a suspicion of adenomyosis by laparoscopy. But not all uteruses that have adenomyosis can be diagnosed by laparoscopy. So that’s not the gold standard.
Yes, of course, it’s not the same to undergo an egg donation program and to have IVF cycles with your own eggs. There are different budgets and they vary according to each patient. Of course, you can have the budgets for each procedure. Right now I don’t have that information to provide you with. If you want to contact the clinic, we will be delighted to give you all the information you need. Of course, it’s not the same if you have to undergo fresh embryo transfer or do genetic testing or undergo hysteroscopy – then you have different costs. It’s not the total cost for one thing that we propose because not all patients need all of that. Each treatment is defined by what each patient needs. So we don’t have approximate costs. But you can have access to that information by contacting the clinic.
No, it’s not a rule one. We only perform PGD in egg donation programs when the male partner has a chromosomal abnormality that needs to be tested in the embryo. Donated embryos, coming from other couples who underwent treatments and want to donate their left embryos, are sometimes tested because of male factors. But generally, we do not test donated embryos. Why? Because in the case of embryos coming from egg donation programs or double donations (with egg and sperm donors), the age of the donor is the best prognostic factor of healthy embryos. If the donor is under 30 years old, 4 in every 5 embryos would be normal. Of course, we always have the chance of getting an abnormal embryo but that’s not a rule. So donated embryos are not tested – at least, not all of them. Because if we test them, not all embryos will survive thawing. And that’s something that you have to know. So we do not test all of them – only the ones that apply.
It depends on the patient. If we have a 42-year old and good day 5 embryos, we usually test them. It depends on the quality of the embryos and the history of that patient. Of course, being 42 is an indication for PGT just to rule out abnormal embryos. Because the chances for you to have abnormal embryos are higher. At the age of 42, only 1 in 10 blastocysts would be normal. So yes, it’s a good thing to test them – if the quality and the cohort allows us to do it. But sometimes we just have to go ahead and give that embryo the best chance it has in a well-prepared uterus and well-prepared endometrial lining. So sometimes we have to take risks. But usually, the indication is to do PGT.
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