Causes of embryo implantation failure in IVF programs

Esther Marbán, MD
Gynecologist & Fertility Specialist at Clinica Tambre, Clinica Tambre

Category:
Embryo Implantation, Failed IVF Cycles

From this video you will find out:

what the embryo implantation procedure looks like
what clotting alterations are
what immunological alterations cause the implantation failure
how uterine factors reduce the chances of implantation
the role of endometrium in implantation success
how to assure the best semen quality
the criteria for classifying embryos

Causes of embryo implantation failure in IVF programs

What are the reasons for an embryo failing to implant in IVF program?

Implantation failure is a sad but quite common fact in the assisted reproduction reality. However sad and unfair it may seem, it is important to know its background and the most common reasons. In this webinar, dr. Esther Marbán Bermejo, Gynecologist & Specialist in fertility at Clinica Tambre, is talking about the causes of failure of an embryo to implant in the IVF cycle.

Understanding embryo implantation

To know the reasons for embryo implantation failure, it is important to understand embryo implantation itself. Dr. Esther Marbán Bermejo explains it as a procedure by which an embryo (mostly at the blastocyst stage) joins the maternal endometrium to carry on its intrauterine development. There are different stages the embryo has to follow to implant: hatching (when the embryo starts to get out from its external membrane – zona pellucida), apposition (when the embryo approaches the endometrium so that the internal cell mass points towards it), adhesion (when the embryo joins the endometrium) and invasion (when the embryo starts to go inside the endometrium to implant). All the stages have to be followed properly in order for the embryo to implant successfully.

The embryo implantation success generally depends on a few factors and these are gametes quality (eggs and sperm), embryo quality, a technique and a proper moment to do the embryo transfer, a proper dialogue between the embryo and the endometrium and – last but not least – suitable luteal phase support.

Decreasing the embryo implantation chances

The implantation failure is defined as a failure to achieve a pregnancy in women younger than 40 years old after having transferred at least 4 good quality embryos (in cell stage) in both fresh and frozen embryo transfer. Dr. Esther Marbán Bermejo admits that the latter is a classical definition but in the current clinical practice, doctors do not wait to transfer 4 embryos. Nowadays embryos are generally transferred at the blastocyst stage in order to increase implantation and pregnancy rates. Doctors do at least 2 good quality blastocyst transfers and then – when a patient fails to get pregnant – they start to think about implantation failure.

According to dr. Marbán Bermejo, there are many factors that can affect the implantation – but they are not always the cause itself. First of all, women over 40 years old have a decreased implantation rate. The reason is the quality of the embryos: if the embryo is not chromosomally healthy, it has a lower chance of implanting. That’s why – in order to increase the chances of implantation – it is very important for the embryos of over 40-year-old women to undergo pre-implantation genetic screening (PGS). Secondly, if a woman is older than 40 years old and has a low ovarian reserve, the number of embryos available to transfer and freeze will be significantly decreased. As a result, the chances of implantation go down as well. Thirdly, medical conditions such as endometriosis or hydrosalpinx can affect the implantation negatively. The same refers to uterine cavity alterations, such as polyps or fibroids. In any case, when there is the so-called ‘disturbing’ factor in the uterine cavity, the embryo will have a lower chance of implanting. Fourthly, inappropriate endometrium development can also result in a decreased implantation rate. Here the conclusion seems obvious: in order to boost the implantation rate, we have to put the embryo in the best endometrium and in the best conditions possible.

Immunological causes of embryo implantation failure

Among all factors that affect the embryo implantation process and – consequently – reduce its chances of success, immunological alterations seem like the most common problem. According to dr. Marbán Bermejo, immunology and reproduction are really closely related. The first issue to consider in the case of immunological disorders is the presence of anti-thyroid antibodies. Dr. Marbán Bermejo always asks her patients to test a thyroid-stimulating hormone (TSH) level as well as some antibodies (anti TPO AB). If the latter is positive and the TSH level is over 2.5, there is a need of introducing a specific treatment called Levothyroxine (Euthyrox®). It is very important for anti-thyroid antibodies to be under really strict control – otherwise, the risk of having a miscarriage or a failure of implantation is significantly increased. The same happens with antiphospholipid syndrome (APS) – there are some basic antibodies to be tested, such as e.g. antinuclear antibodies (ANAs), anticardiolipin antibodies and lupus anticoagulant. Patients that test positive for these antibodies generally have a history of previous miscarriages or even thrombosis. In such a situation, it is really important to do a proper treatment followed by Aspirin or Heparin (or both) to decrease the risk of having another miscarriage or even a failure of implantation.

Dr. Marbán Bermejo describes pregnancy as a procedure with immune tolerance. The immune tolerance in such a case is the absence of a maternal response towards the foetus – meaning that the woman’s body doesn’t react negatively to the new human being. However, there are some patients who don’t have a very well-balanced immune system – and this results in natural killer cells (NK) expansion in blood or in the uterus. Such patients have a higher chance of having a pregnancy loss or an implantation failure. Dr. Marbán Bermejo says that when such patients are identified, they are contacted with an immunologist who decides about the best type of immunotherapy which may include corticoids, intralipids or gammaglobulines. All of the latter have proven to increase implantation and pregnancy rates.

Another part of immunological system is the combination of HLA and killer cell immunoglobulin–like receptor (KIR) genes that have been associated with diseases such as autoimmunity, viral infections, reproductive failure and even cancer. If patients are lacking most or all activating KIR (AA genotype) – and the foetus possess HLA-C belonging to the HLA-C2 group – they are at risk of implantation failure, recurrent pregnancy loss and some pregnancy complications, such as high blood pressure, preeclampsia or intrauterine growth restriction. To avoid the risk, the patients going for egg donation treatment should have their donors selected in the relation to the immune system. Patients planning IVF with their own eggs can have an immunomodulator treatment added. It is equally important to choose a single embryo transfer – otherwise, in case of transferring two embryos, the patient is put at risk of a double load of HLAC. And this may provoke an even stronger reaction from the immune system.

Dr. Marbán Bermejo also mentions celiac disease as one of the important immunological disorders endangering a successful pregnancy. The disease is caused by an intolerance to gluten and is especially risky in the case of patients who were left untreated or who haven’t been diagnosed yet. Apart from well-known digestive alterations, this disease can be related to the failure of implantation and miscarriages. That’s why it is important to test some antibodies against celiac diseases (anti-tissue transglutaminase and anti-gliadin antibodies) to make sure that they are negative. In case they are positive, patients – especially those with a history of implantation failures and miscarriages – should follow a gluten-free diet to have their results improved.

The role of endometrium in the embryo implantation

According to dr. Esther Marbán Bermejo, inappropriate endometrial development can reduce pregnancy and implantation rates. Desired endometrium should be between 7 and 12 millimetres thick and have triple-line pattern. However, some patients can have problems with achieving these ideal parameters before the embryo transfer. In such a case, doctors can prepare their endometrium – either by taking advantage of their natural cycle (and oestrogen pills) or by using some specific treatments, such as gonadotropins, Aspirin, Viagra or Pentoxifylline.

Another issue related to the endometrium is the window of implantation (or endometrial receptivity). It is known as the period of time when the endometrium has the best conditions for embryo implantation. In most cases, it happens between the 19th and 21st day of the natural cycle. However, dr. Esther Marbán Bermejo admits that 30% of patients have the window of implantation displaced. Fortunately, nowadays there is the opportunity of testing the endometrial receptivity to ensure a personalised embryo transfer at the correct moment. The test – called EndomeTRIO – can also be used for analysing endometrial microbiota and chronic endometritis. In case it shows any kind of inflammation or the lack of beneficial lactobacillus bacteria in the endometrium, some specific antibiotics treatment should be introduced.

Uterine and blood clotting reasons for a failure

Clotting alterations is another, after immunological disorders, serious cause of implantation failures. Dr. Marbán Bermejo says that one of the most typical and most common tests that she asks her patients to do are hereditary trombophilias (Factor V Laden, F II Mutation, MTHFR Mutation, F XII Mutation). The same refers to PROTEINE C AND/OR PROTEINE S DEFICIENCY and ANTITHROMBIN (AT) III DEFICIENCY. In case doctors find any of those alterations, they send the patients to a haematologist who adds some specific treatments such as Heparin or Aspirin (or both) in order to avoid affecting the implantation procedure.

Dr. Marbán Bermejo stresses the importance of the uterine environment for the success of the embryo implantation. That’s why all possible uterine alterations should always be closely assessed and dealt with – mostly with surgeries. These include intracavitary alterations (such as fibroids) that can be diagnosed using a vaginal scan complemented with 3D ultrasound and Asherman’s syndrome caused by post-surgery scars in the uterine cavity (and observed during a hysteroscopy). Another type of uterine alterations is hydrosalpinx which refers to a fallopian tube blocked with liquid that can be toxic for embryos. This condition is most commonly diagnosed with a scan and removed with salpingectomy (fallopian tubes removal). Uterine malformations, on the other hand, can be diagnosed and treated with a hysteroscopy. According to dr. Marbán Bermejo, the latter can be used for a successful removing of a uterine septum and – as a result – increasing the chances of embryo implantation.

The importance of the male factor

As all the mentioned factors relate closely to the female side of the reproduction process, male causes should be taken into account as well. Surely, it is important to conduct semen assessment, including basic semen analysis ( volume, concentration, motility and morphology) as well as more specific tests. One of them is single/double stranded DNA fragmentation test (Comet FertilityTM ). A high rate of single stranded DNA fragmentation is connected to a lower fertilisation rate while a high rate of double stranded DNA fragmentation results in higher chromosomal alterations risk in the embryo. In the end, both types of fragmentation lead to lower chances of successful embryo implantation. Dr. Marbán Bermejo says that, depending on the alterations found during this test, the specific treatment should be added to reduce the fragmentation. Doctors can introduce antioxidants or turmeric and recommend a healthy lifestyle (without smoking, alcohol and excessive coffee intake).

Another important issue in assessing the male factor is genetic semen tests: Chromosperm and FISH. There are several techniques to check the chromosomal content of the sperm – and this is crucial while DNA alterations in the sperm lead to a higher number of non-healthy embryos.

The embryo and its quality

Dr. Esther Marbán Bermejo admits that one of the most important factors for successful embryo implantation is the embryo itself. Its classification should be conducted according to the criteria such as cell number, the percentage of fragmentation, nucleation, alterations and cell division moment. In order to determine the latter and understand how embryos are dividing, new technologies as Time-Lapse incubators are used.

In dr. Marbán Bermejo’s opinion, the embryo quality is the aspect doctors should always pay most attention to. It should always be good or – at least – intermediate. The embryo has to be well-developed, with regular cells, and chromosomally healthy. The latter feature is, in fact, the most important. It is true that the older the woman gets, the more unhealthy embryos she will have. That is why the role of pre-implantation genetic screening (PGS) is so crucial here. It helps to exclude chromosomally abnormal embryos and choose the ones that may help in increasing pregnancy and implantation rates.

After the embryo transfer

In order to increase the chances of the embryo implantation success, dr. Esther Marbán Bermejo gives patients some recommendations regarding proper behaviour after the embryo transfer. According to her, it is important to avoid intense physical activity and sexual intercourses and follow all the prescribed medications – to maintain the endometrium in an unchanged state. Some bad habits, such as drinking alcohol and smoking, will not prove beneficial either – so it is necessary to restrain from them straight after the transfer and during pregnancy. All of this may help increase the embryo implantation rate as much as possible – and help patients make an important step towards the dream of parenthood.

- Questions and Answers

What is your opinion on multiple miscarriages due to having recessive carrier conditions such as: 1. hereditary fructose intolerance ALDOB c.1005C>G (p.Asn335Lys) autosomal 2. Leber congenital amaurosis 10/CEP290- related disorders 3. Recessive for CEP290 c.5493delA autosomal (p.Ala1832Profs*19)?

I think that the patient has done a recessive carrier test and that test is not related to the implantation itself. That test is going to tell the patient if they are carrying a mutation on their genes that can result in their baby suffering from that illness. All the recessive illnesses that have been tested in that test are not related to the implantation. It means that the patient is carrying those recessive disorders – but it’s also important to know if the partner status is the same or not. If, for example, the woman was carrying cystic fibrosis, which is one of the most common mutations, and her partner was carrying the same mutation, 25% of their offspring would have the disease. But if the woman is carrying the mutations and the partner is not carrying any of them, then there won’t be a problem – the genetic risk they are going to take is really low and that test is not related to the implantation. But multiple miscarriages the patient has had are not related to the mutations she’s carrying. Maybe she should do a more specific test like a karyotype, which is quite simple, and some other tests to see what’s the reason of all her miscarriages. The mutations she’s carrying are not related to the miscarriages she’s had.

I had a miscarriage and a surgical procedure (D&C) three weeks ago and I am due to have a frozen embryo transfer (FET) next month. What can I do to improve my chances of a successful implantation? I have endometriosis. I’m interested to learn of any medication, treatment or special diet to introduce ahead of my FET next month.

It could be important to try to have a healthy life, I think it’s quite obvious. Apart from that, if you have endometriosis, sometimes it would be good to do a hysteroscopy because endometriosis can affect the endometrial cavity. Patients with endometriosis may have some alterations, such as adenomyosis, inside the uterine cavity or even in the uterine wall, so sometimes we ask them to do a hysteroscopy to be sure that the endometrial cavity is fine. We also ask them to do magnetic resonance to see if the uterine wall is fine because sometimes endometriosis can affect the uterus – apart from the ovary. Of course, it would be also important to study alterations in the endometrial microbiota and chronic endometritis because sometimes the cause of a miscarriage is an infection inside the uterine cavity – even if the patient didn’t have any specific symptoms. So when a patient had a miscarriage, in my opinion, it’s very important to take the whole clinical case into consideration. We should know the age of the patient, the quality of the embryos, if the embryo has been tested previously if APS was done, etc. Having a miscarriage, if you are 39 years old and the embryo was not tested, is not the same as having a miscarriage at 39 years old when the embryo was tested. All patients are not the same – they are very different from one another and it’s very important to have a very personalised approach to their problems. So I think that in this situation a hysteroscopy could help in seeing the uterine cavity. The patient had surgical management of the miscarriage so it could be important or at least interesting to see the uterine cavity to be sure that everything is fine there.

My implantation failed when I was 43 years old. I was given treatment for natural killer cells/ antibodies before the transfer took place. I was encouraged by the medical director to drink a litre of milk a day to help the implantation. When the implantation failed, the clinic could not explain why. Do you have any suggestions? This was a clinic in London.

I can’t answer that because this is the first time I hear that someone recommends drinking a litre of milk. Maybe it is about minerals and vitamins milk has – but actually, I wouldn’t recommend doing it to any of my patients. I think it’s much more useful to drink more water and to eat properly – I mean lots of fruit and vegetables, etc. Of course drinking milk is important but I wouldn’t recommend drinking a litre of it a day. So for me it’s very surprising to know that some doctor recommends that. I suppose that results from his experience – maybe he observed that things were going better then. But I can’t give you any advice on that because for me it’s very strange.

I must add that I have hypothyroidism. I stopped taking Levothyroxine because it was making me feel ill. Should I keep taking it to help the implantation in the future?

I would recommend testing TSH (thyroid) level so that we can be sure that it’s below 2.5. So if it’s below 2.5, I’d recommend going on with the medication. Sometimes we need to increase the dose of Levothyroxine to try to have TSH level below 2.5 – just like it’s needed. Here in Spain, it is very typical to test TSH level every trimester. The patient should go on with the medication for at least the first trimester and depending on TSH level, the doctor has to decide whether to increase or decrease the dose. Normally, the doses have to be increased because during pregnancy, women need a higher dose of TSH – of Levothyroxine. So my advice would be taking Levothyroxine without stopping and testing TSH before doing the next embryo transfer.

Should we do an ultrasound before starting the treatment to proactively check if we have any issues?

Of course! My advice is to do a vaginal ultrasound. It is very easy to do and it’s not harmful to the patient – it’s not like radiation. In this way, we can be sure that there’s no issue inside the uterine cavity, or even in the uterus. Sometimes we can see if a patient has a hydrosalpinx issue, etc. So it’s a very easy test to do and it can help us a lot. If we diagnosed any alteration in the tubes or in the ovary or even in the uterus, we can solve this situation before starting the treatment. Otherwise, it could be difficult to deal with the problem if the treatment has already started. So I would recommend doing it for sure.

Is it normal to have the endometrium thickness of 7-8 mm after menopause?

Actually, if a woman is after menopause, it’s not very common to have that thickness of the endometrium. When we find out that a woman is after menopause and she is not using any oral medication – that I suppose is the situation here – it is important to do an endometrial biopsy to test how the endometrium is doing. Sometimes we can find e.g. hyperplastic endometrium and it’s important to take such conditions into consideration. Women after menopause should have a much lower thickness of the endometrium – below 5 mm. So it’s important to do another scan in case we check it again and it’s still around 8 mm. It would be needed to do an endometrial biopsy to discard any pathological alterations.

If the endometrial lining is healthy and has triple-line pattern but it only 6.5 mm thick, does that greatly reduce the chances of implantation?

Of course, the thickness of the endometrium is important but I would say that triple-line pattern is even more important. So if it’s perfect triple-layer endometrium and it’s not reaching that 7 mm, we sometimes wait more days. We may also increase the doses of estrogens or use different estrogens. But even if we don’t reach 7 mm and we have that triple line pattern, we can go ahead and do the embryo transfer. Of course, if the thickness is like 5 mm, it’s important to reach at least 6.85 mm or 7 mm – but if it’s 6.5 mm, then it’s enough.

I am 47 and I had three IVFs with own eggs and no implantation. Then I did one egg donation cycle – the embryo implanted but I had a miscarriage at 7 weeks. Can I still have a baby? What should I check – especially for the implantation problem?

When we do egg donation treatment and especially if we transfer embryos at the blastocyst stage, the chances of getting pregnant are really high. So in the case of this patient, I would recommend testing for some alterations that I have mentioned before, such as clotting alterations and immunological alterations. I would recommend doing a specific 3D scan to be sure that everything is fine in the uterine cavity and I would ensure that the transferred embryo is of good quality. Keep on doing the embryo transfer but first of all, get tested for immunological and clotting alterations because these are the most common factors to be affecting the implantation.

Is the ERA test from Igenomix the same test as the ER Map done by iGLS laboratory in Alicante? Does it tell us the same information or is one of them better than the other?

Actually, they’re almost the same. The difference is in the genes that these tests check – so the ERA test has its own genes to be tested and the ER Map has different genes. The problem we have is that we are not very sure what genes are affecting the implantation procedure. We normally use the ERA test but of course, there are some other tests as well and all of them are valid are useful – so I couldn’t say that this one is better than the other. It depends on the clinic because some clinics are used to doing some kind of tests and others prefer to do different kinds of tests. But in the end, the information these tests provide is quite similar. I’m sure that both of them can help in finding the window of implantation and that is what we are looking for.

Is it advisable to do the ERA test prior to a fresh cycle if previous runs were not successful?

When we use the ERA test in a fresh embryo transfer, the only problem we have is that the treatment we follow to do the ERA test has to be the same as the one we follow when we want to do a fresh or a frozen embryo transfer. If we use some estrogen pills to prepare the endometrium, then we add progesterone and then we do the embryo transfer, we have to remember that in case of a fresh embryo transfer, those estrogens will be different and the procedure of preparing the endometrium is different. So the ERA test will tell us how things are and where the window of implantation is, when we are using the same protocol and exactly the same medication. If we change the medication that we use, the ERA test results won’t be useful as we can’t be sure that the situation in the endometrium will be the same. So if we are thinking of doing a fresh embryo transfer and the ERA test was previously done in a frozen embryo transfer cycle, we have two different options. The first one would be freezing the embryos and then doing exactly the same preparation to do the next frozen embryo transfer – it could be one option. The other one would be not taking into consideration the ERA test and just doing the fresh embryo transfer. So if you have done that test, I think it would be important to consider the results and to do the embryo transfer at the exact moment the ERA test tells us to do.

How much does the ERA test cost?

It depends on the clinic and the country but I think it is between 700 and 900 Euros.

Is it enough to do just one of these tests: the ERA test or ER Map? I have done ER Map – is it enough or is it recommended to do the ERA test as well?

It doesn’t matter as both the ER Map and the ERA test tell us if the endometrium is receptive. It means that we have to do the same protocol as for the next embryo transfer. If it’s possible, it is important to do the next embryo transfer as close as possible to the ER Map or the ERA test. The results won’t of course change much in a few months or even years after doing the test but it’s important to do it as close to the test as possible. In case you decide to do e.g. the ERA test, we recommend you to do what we call the EndomeTRIO test – it includes the ERA, endometrial microbiome and chronic endometritis tests. So we are used to doing a wider examination and a wider test. In the end, it’s a very personal decision but once the patient decides to do a test on the endometrium, we recommend doing the most complete one to have everything under control. The ERA test can be done in a natural cycle. And it means that we won’t use any medication.

Can the implantation window change depending on the medications or protocol we follow before the ERA test?

As I was saying before, the implantation window can change depending on the moment and depending on the medication we are using. The ERA test is going to test different genes expression that will be happening in that window of implantation and at a specific moment of implantation. And some treatments, such as estrogens or the Heparin treatment, may change that genetic expression. So in the end it’s so important to follow exactly the same treatment when we do the ERA test and the embryo transfer – so that the results can be almost the same in each situation. All laboratories say that there won’t be any changes in the window of implantation but it’s very important not to change the protocol – otherwise, the results cannot be the same.

I had a chemical pregnancy with a PGS-tested normal embryo. Since then, I have also done the ERA test which came back post-receptive. I am now repeating the biopsy to determine my correct window of implantation. I also tested for NK killer cells and these were slightly elevated. My clinic is no longer offering treatment because of COVID-19 risk. My doctor said the ERA test result was much more significant as the science for natural killer (NK) treatment is still unproven. Do you agree?

If we have several alterations and several issues in the same patient, it’s very difficult to put them in the balance and say that e.g. the ERA test is more important than the NK cells test. So in the end, we try to do our best and we try to offer the best treatment for the patient. Determining that the problem is just a matter of the window of implantation or is just a matter of NK cells is not so easy. I would say that almost all patients have many factors that can affect negatively the implantation or even the miscarriage rate and it’s very difficult to say that one of them is more important. So maybe it would be advisable to wait until that coronavirus situation ends or at least improves to have the opportunity of doing a specific treatment and to avoid the situation when NK cells affect the implantation negatively. It’s true that NK cells study and examinations are kind of controversial because there are some publications that say we can increase the prognosis rate if we use specific NK treatment and some others find no significant benefit to that. In the end, it depends on each clinic and on each doctor. But I would recommend taking both the ERA test and NK cells into consideration. Sometimes it’s better to wait one or two months to have the opportunity to be treated with that NK cells alteration.

Is endometrial microbiota tested on a sample taken during the uterus biopsy?

Actually it can be tested at different moments. It’s only important to do this in the luteal phase, so after the ovulation. It is done by taking a sample from the endometrium and doing normal culture so we can see if the bacteria that are inside the uterus are the ones that have to be there. Normal culture sometimes misses some kind of bacteria that are positive so we normally recommend doing a specific test called the EndomeTRIO. But of course, it can be done with a normal biopsy in the luteal phase and with normal culture to see if the bacteria that are inside the uterus are the lactobacillus – the ones that are beneficial for the implantation.

I have had five donor transfers. 4 failed and I had one early miscarriage at six weeks. I had ER Map test, KIR and now I’m on the immune protocol. I had good uterus lining shown on the transfer. Would you recommend any other tests?

I think that maybe the sperm hasn’t been tested before. First of all, I would do the fragmentation test on the sperm and after it’s done, I would test the embryo, too. Of course, egg donors are really young and the percentage of unhealthy donor embryos is not very high but we see that some patients, for different reasons, have a higher number of non-healthy embryos anyway. So in the case of 4 failed treatments and one miscarriage, I think it would be important to test the sperm and the embryo as well.

If a successful pregnancy live birth was achieved a few years ago, does this rule out certain implantation failure causes?

It’s true that in a patient who had a previous pregnancy and everything went well, the chance of having implantation failure will be decreased a lot. Of course, it will also be related to the current situation that patient has. It’s true that if a patient had a previous pregnancy that ended perfectly well, it means that at least at that moment her body was perfectly prepared to let that pregnancy go on. But it doesn’t mean that a failure of implantation won’t appear at any moment in this woman’s life. Of course, it’s more common to speak about implantation failure in women who didn’t have previous pregnancies or at least didn’t have a live birth baby at home. However, we sometimes find patients who had a previous pregnancy without any specific problems and then, in the next embryo transfer, things start not to be so easy. So if you have had that previous pregnancy, your chances of implantation failure will surely be decreased – but they won’t disappear.

How long before FET (frozen embryo transfer) should we be prepared in terms of a diet and exercises? Are there any specific vitamins, food or holistic treatments that you recommend?

As I’m Spanish, I would recommend a Mediterranean diet full of fruit and vegetables, avoiding red meat and so on. The earlier you can start having a healthy life, the better for you. If you can do it for at least three months before the embryo transfer, it would be good. It’s important to avoid smoking and not to drink much coffee or coke or that kind of drink. Always, if a patient can start a healthy way of life some months prior to the embryo transfer, it is much better. But of course, we understand that sometimes it is not so easy so I would recommend at least two or three months.

How do you test chronic endometriosis? How is it cured? Is it cured with Amoxicillin?

Actually, it is chronic endometritis – and not endometriosis. It’s a different thing. So chronic endometritis is when we find some infection inside the uterine cavity. Normally, it’s not related to any symptoms but we can test it with very specific markers. One of them is the plasmatic cells – the markers of chronic infection and sometimes we test a very specific marker called CD138 which is going to mark these cells in the end. If we find those cells in the endometrial biopsy, we can start a specific antibiotic treatment to avoid having that infection inside the uterus. So normally we need to test it and we need to repeat the endometrial biopsy so that we can be sure that chronic endometritis has disappeared.

I have heterozygous MTHFR gene variant. I do take folate and I’m gluten and milk free. All clotting tests were negative but I have had a blood clot a couple of times in my life. We will now try Nivestim, Januvia and Metformin in my 12th embryo transfer. My uterus is clear. What advice would you give us? I have taken the ERA test. My hypothyroidism is also taken care of.

It seems that the patient has gone through quite a wide examination and a lot of things are under control. So in that situation, I think the embryo should be tested in the way depending on the age of the woman. The quality of the embryo is very important as well as the day of the embryo transfer. If possible, the embryo should be transferred at the blastocyst stage because we know that these kinds of embryos have a higher rate of implantation. If the woman is older than 40 or even 38 years old, the chances of having an unhealthy embryo will increase. Of course, the clotting alteration may sometimes affect the implantation but it’s really important to test the embryo before doing the embryo transfer. If the patient has done all the tests on immunology, on clotting, on endometrial factors, the only factor which is missing is the embryo and the sperm itself. Of course, if the embryo is already there, it is not recommended to test the sperm because it doesn’t make any sense. But it is important to test the embryo. If the embryo is not healthy, we can add as many treatments as we want and the embryo would still have a lower chance of implanting. So it would be important to have all the information on that patient and it would be important to test the embryo before transferring it.

Could you suggest other things than testing the embryo and sperm, please?

Actually, here the patient has tested almost everything. If the ERA test was done and it was receptive, my only advice would be doing a hysteroscopy to see if there is no alteration in the uterine cavity. All the endometrial cavity should be tested with hysteroscopy or even by doing an endometrial biopsy to test the endometrial microbiome or the plasmatic cells and see if there is no chronic endometritis. When it comes to MTHFR, taking some folic acid will help in not affecting the implantation negatively. That alteration is quite common and it’s not very severe but if the patient has had several implantation failures or even several miscarriages, sometimes some haematologists decide to add Heparin or Aspirin to the treatment to increase implantation and pregnancy rates. Depending on the situation, Aspirin/Heparin is needed to be used at least one week prior to the embryo transfer and then it has to be followed from there throughout the first trimester of the pregnancy. Sometimes it has to be kept on throughout all the pregnancy. Of course, there are many factors that are affecting the implantation and it’s very difficult to say which factor is the one that is affecting the most. But we know that some treatments can be used quite safely and the results can be improved. However, it’s true that sometimes we don’t know what’s going on and what’s happening because the patient doesn’t get pregnant – then we have to think about other factors or at least try to re-think the situation once again. Fortunately, such situations are not very common.

Are dairy products bad for endometriosis?

Endometriosis is a well-known condition but at the same time, we still have so many doubts about it. I wouldn’t say that dairy products are bad for endometriosis but we know that for some patients, who have some kind of celiac disease, it is not recommended to take dairy products. There is some kind of food or some kind of vitamins (such as vitamin D) or minerals that can affect the implantation. I would say that milk and some other products can affect the immunological system and put it out of balance before the implantation. We have some publications and some data about that but of course, it’s not the only thing to take into consideration. So in the end, it’s important to have a healthy lifestyle. When it comes to endometriosis, it could be another issue to talk about for hours. However, there are some products that are not recommended because they can affect the implantation negatively – we are still not very sure why but we simply know they can affect it.

Do you mean we should take vitamin D? If so, how much per day?

It depends on the vitamin D value that the patient has. We normally test vitamin D level and after testing, we decide about the dosage. In case of vitamin D, the normal level is over 30 ng/mL – so for example, if the patient has 63 ng/mL, it is a normal value. Some patients need to increase the value – we normally add 1000 units per day but it depends on the patient. It’s especially recommended in some countries where there is not much sun during winter. So if we are not very exposed to the sun, the vitamin D level will be decreased and we should supplement it.

Is it equally important for men to take vitamin D?

Day by day, we know more about what men should do for better embryo development but vitamin D is not so very important here. It is crucial for the bones and the metabolisms and so on, but not for sperm development. Of course, men should have a healthy way of life, etc. but vitamin D is not especially important for them in the reproductive situation.

What vitamins are important for men to take?

We can find many different brands in the pharmacy – they add some vitamins, selenium and some other minerals to improve the sperm quality and try to decrease DNA fragmentation. Turmeric is known to decrease double strand sperm DNA fragmentation and actually we normally use Turmeric pills in our patients. The reason is that they are very powerful antioxidants and they reduce the fragmentation. And in the end, we can have better results of the implantation if the sperm is in the best condition.

Is turmeric okay if a man has a small kidney stone?

Of course, I’m not an expert in kidney stones but I would say: yes, it’s ok. Turmeric won’t affect kidney stones in any way. The doses we are using are not very high so it can be used in almost everyone.

Is turmeric good for women during the implantation?

Turmeric is a very powerful antioxidant. From what we have known so far, it is not related to the implantation itself. We know that it can help in some kind of situation, such as DNA fragmentation and in some women who have a really low ovarian reserve or very bad egg quality despite being young. We know that sometimes the problem is the oxidation and the environment in their ovaries. So in such a situation, some antioxidants could help – and especially Turmeric. As far as I know, there are not many studies on that but Turmeric is just antioxidant and it won’t be harmful to the patient. I wouldn’t say that it would help with the implantation but it won’t do any damage to the patient either. So if it can be used, then why not?

What about probiotics and organic flaxseed oil?

We have plenty of experience in the use of probiotics. As I was mentioning before, after the antibiotics treatment, some probiotics are recommended to try to put endometrial microbiota and the genital area in the best condition. Actually, when we test the endometrial cavity, chronic endometritis and that kind of problem, we see that some patients have different bacteria in the uterine cavity. And if we don’t have lactobacillus – which are the bacteria that will help us in getting pregnant – we can have lower pregnancy and implantation rates. So sometimes we don’t find any specific infection but we see that the endometrium microbiota is not as good as it should be. In those patients, we can add some probiotic treatment to try to have the endometrium and endometrial microbiota in the best condition. These products are really useful for us.

Do you recommend probiotics administered orally or only vaginally?

It is more recommended to use them vaginally. The reason is simple: if you take them orally, some of them can be like deactivated by the stomach and its fluids. If you take them vaginally, they are going to be very close to the uterus and to the endometrium so they will act faster. The concentration of the bacteria would be much more increased if they are used vaginally.

A few years ago some doctors were giving Amoxicillin to RIF ( recurrent implantation failure) patients preventively before the embryo transfer. Do you think it could help to go for a 10-day Amoxicillin treatment to avoid the risk in case of some endometrial inflammation or chronic endometritis? I got pregnant with ET (embryo transfer) only once and it was the cycle after Amoxicillin treatment. Do you think it could have a positive effect? Unfortunately, the pregnancy stopped after 7 weeks due to embryo aneuploidy. I was 40 at that time and my endometrium has always been perfect – triple-layer of minimum 8 mm.

Now, when we have the opportunity of testing endometrial thickness and endometrial cavity before doing the embryo transfer, I wouldn’t recommend using Amoxicillin preventively because we don’t know if it’s going to be useful or not. Actually, when we have bacteria inside the uterus and we have chronic endometritis, Amoxicillin is not enough. I think that using Amoxicillin won’t help us so instead, I would recommend doing an endometrial biopsy and then taking the results into consideration. Sometimes, after we use some antibiotic treatment, we normally follow with probiotics to try to remove the bad bacteria first and then to have the good bacteria back to the endometrium. The fact that the patient got pregnant after doing Amoxicillin treatment was a coincidence – I’m pretty sure that Amoxicillin wasn’t the reason. These were just two events done in the same cycle and I think that Amoxicillin treatment didn’t affect the implantation and didn’t help in that situation. Getting pregnant was just a matter of chance – and that’s all.

At what day of the cycle should I do the biopsy?

When we are talking about the biopsy to check the endometrial microbiome and chronic endometritis, it has to be done in the luteal phase. It means if the patient has, for example, a cycle of 30 days, it has to be done between the day 18th and 21st approximately. So the way we calculate it should depend on the length of the cycle of the patient. If we are doing the ERA test, we normally do everything at the same time. So we do the endometrial preparation and then we do all the tests on the endometrium with just one biopsy.

Do you have any tips on the implantation? I’m 42 and I had a miscarriage at 38. I have been through 5 retrievals with 10 fresh and frozen transfers – 2 of those were on me and other 8 on surrogates because I had Asherman’s syndrome. Doctors say that all eggs of mine are of good quality. What would be the issue? Lastly – is it safe to be on antibiotics on the day of the transfer?

No, I would not recommend using antibiotics unless there is an infection at that moment – but if there is one, of course I wouldn’t do the embryo transfer then. If the patient has transferred so many embryos, it would be important to do some specific tests. First of all: if she was 38 years old at the moment of a miscarriage – and we know that the chances of having chromosomal issues in the embryos are going to be increased then – I think that the embryos should be tested before the transfer. Because of all those possible chromosomal alterations over the age of 38, the embryo is the most important factor here.

Do you always recommend the blastocyst transfer? Even if there is one clear candidate for the embryo transfer on day 3? Does the embryo have more chances of developing externally or is it best to transfer it earlier, providing that the endometrium is ready?

The current recommendation is doing a blastocyst stage embryo transfer. There are many reasons. One of them is the following: in case we have a patient who’s had many embryos on day 2 or day 3, and the embryos are quite similar in the quality, we can wait two or more days to select the best embryo. So when we do a blastocyst embryo transfer, we are able to get a very good quality embryo and we recommend doing a single embryo transfer. In this way, we will reduce the chance of having a twin pregnancy. Apart from that, it’s true that in case of embryos that have really good quality on day 3, things often change on day 5. Then the sperm starts to appear – some male factors can be visibly better than earlier. Some embryos, that on day 3 are of perfectly good quality, stop in their development on day 5. And we won’t know that if we transfer the embryo on day 3. So my advice and our recommendation is doing the embryo transfer always on day 5. Of course, some patients have just one embryo and they are very afraid of what will happen if the embryo doesn’t reach the blastocyst stage. Nowadays, with all the technology and culture media that we are using, we know that if the embryo doesn’t develop properly in the laboratory, it’s very likely that it won’t happen in the uterus either. Of course, the best incubator is the uterus – we all know about that. But now we can see that the conditions in the laboratory are almost the same. Of course, it depends on each situation and we have to be very careful in the advice we give, but I would recommend doing a blastocyst stage transfer in almost all the cases.

You have mentioned to avoid sex after the embryo transfer – however, sometimes in days after the transfer, involuntary orgasm may occur during sleep due to a high level of hormones. Can this affect the implantation?

No, it can’t. I meant that having some kind of sexual intercourse can affect the implantation – in relation to movement and so on but not to orgasm itself. What we mean is that a patient should try to have a relaxed life in the first three or four days after the embryo transfer and then they can have a completely normal life.

Does the administration of Heparin have influence on the implantation window?

Actually, it does. So if the patient is undergoing Heparin treatment, we always add that treatment when we do the mock cycle to prepare the uterus for the endometrial biopsy. We know that it can affect the window of implantation – although it’s not very clear why. So if the patient is undergoing Heparin treatment, we should use it if we do the ERA test or the window of implantation test as well.

I am currently taking antibiotics for an infection. I’m going to Spain for the embryo transfer in August (hopefully). Am I leaving enough time between taking antibiotics and the transfer?

Depending on the treatment and the infection, I’d say 10 days would be enough to have all the concentration of that medication disappear from the body. So in order to do the embryo transfer safely, you would need at least 10 days between the treatment and the transfer. Of course it also depends on how long the patient has been on that treatment – so sometimes we need two weeks to avoid having all the negative effects on the implantation and pregnancy.

I am taking coenzyme 10 (Ubiquinol), Vitex, Black Cohosh, etc. Will those supplements cause a problem?

As far as I know, I think they won’t cause any problems. We normally recommend taking some vitamins, such as folic acid (which is very important for pregnancy) or some vitamin supplements (in case they are needed). But when a patient is taking so many supplements, sometimes we are just not sure if they can affect other issues in the body or not. Generally, they won’t affect anything but sometimes they are simply not needed. So if you are taking folic acid and some vitamins – it could be enough.

Should chronic endometritis always be cured?

Saying ‘always’ or ‘never’ in medicine is too risky but normally I’d say it can be cured. It’s very important to do the diagnosis and to be sure that a patient is undergoing the proper antibiotic treatment. So sometimes it is just a matter of finding some antibiotics that the patient needs and following this treatment with probiotics to try to reduce the number of bad bacteria in the endometrium. So I’d say that chronic endometritis can be cured at almost all times – however, there is a small number of patients in whom it is not possible to deal with that problem. Sometimes it’s really difficult to put the endometrium in a better condition – we can add some specific treatments but sometimes it’s not so easy to reach that goal.

Does chronic endometritis prevent the implantation?

When we have an infection inside the uterine cavity, the conditions for the implantation are different – and they are not the best. In the end, all the problems in the uterine cavity, such as infections or different alterations, may affect the implantation. The moment when we are going to put the embryo inside the uterine cavity is very specific – so the embryo has to be healthy and of good quality and the endometrium should be in the best condition, too. If there is something inside the endometrium that is affecting it – such as chronic endometritis – it is also affecting the implantation. That’s the reason why we prefer to test and check our patients before doing the embryo transfer – to be sure that there is no alteration in the way.

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Authors

Esther Marbán, MD

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

Event Moderator

Caroline Kulczycka

Caroline Kulczycka is managing MyIVFAnswers.com and has been hosting IVFWEBINARS dedicated to patients struggling with infertility since 2020. She's highly motivated and believes that educating patients so that they can make informed decisions is essential in their IVF journey. In the past, she has been working as an International Patient Coordinator, where she was helping and directing patients on their right path. She also worked in the tourism industry, and dealt with international customers on a daily basis, including working abroad. In her free time, you’ll find her travelling, biking, learning new things, or spending time outdoors.

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