By fertility experts from Spain.
What causes implantation issues with IVF with own eggs or with donor eggs? What are the signs of embryo implantation issues? And what are the symptoms of implantation issues an IVF patient may have? Watch the webinar and check the answers to these questions. The entire webinar was dedicated to the topic of “Implantation issues and hormonal reproductive defects”.
Embryo implantation is a complex process, which involves many different factors. In cycles of IVF, where an embryo fails to implant, it can be heart-breaking and confusing, leaving patients asking why and how? In this webinar, Dr Alexandra Izquierdo, medical director of ProcreaTec International Fertility Clinic, Madrid, Spain, discusses what implantation actually means, and the different elements required in order for an embryo to implant and continue to grow, into pregnancy and live birth.
“Implantation is the last frontier in assisted reproduction”, said pioneer of in vitro fertilisation, Dr Robert Edwards, and when thinking about IVF, it really is the final hurdle, following hormone injections, fertilisation and the creation of a, hopefully, healthy embryo.
Implantation must happen, in order to create a pregnancy, yet, sadly, even after IVF, implantation is not a given, even with a top-grade embryo. Of course, having a good quality embryo is key and each day an embryo survives, in a laboratory situation, embryologists are able to garner further information, about its viability, providing increased knowledge as to which embryo/s will offer a higher chance of implantation. Pre-implantation genetic screening (PGS) also enables greater insight into embryonic health.
However, alongside a good quality embryo, there are many other factors which can affect whether, or not, an embryo will implant.
Implantation happens when the outer shell, of the embryo, attaches to the cells of the uterine lining, it’s therefore incredibly important that a woman’s body is well prepared, for the transfer; her hormones have to mirror and be in synch with what would happen, during a natural cycle, creating, what Dr Izquierdo describes as; “the window of implantation”.
For a pregnancy to occur naturally, the female body goes through various hormonal changes to prepare for receiving a fertilised oocyte (egg). Ovulation (the release of the egg) occurs, typically monthly, and the hormone oestradiol is produced; oestradiol is the main oestrogen found in women, and one of its functions is to induce the endometrial lining to thicken, preparing itself for the attaching of an embryo. If an egg is fertilised, during a natural cycle, and implants, the newly pregnant body then enters, what is referred to as, the luteal phase, whereby the corpus luteum naturally produces the correct amount of progesterone, required to support early pregnancy. Progesterone stimulates the growth of the blood vessels, which supply the uterine wall, and stimulates glands, in the endometrium, which then nourish the early embryo, helping it to become a viable, ongoing pregnancy. All of which needs to be replicated, when undergoing assisted conception; if there is a hormonal imbalance or thinner uterine lining, then an embryo is likely to struggle with implantation.
Dr Izquierdo explains that in situations where hormone levels are not where clinicians would want them to be, and in cases of OHSS (Ovarian Hyper Stimulation Syndrome) a frozen cycle may be suggested, so that doctors can ensure the correct hormonal balance for a transfer. A similar protocol tends to happen with women using donor eggs and/or embryos, who should also be monitored, and undergo hormone tracking, before the transfer takes place.
It’s important to remember that every person is unique and therefore it’s the duty of clinics to provide a tailormade service for each individual; the window of implantation isn’t necessarily the same for all patients, and the transfer needs to be carefully timed around each woman. As vitrification (freezing) processes are much improved, it means that medical teams now don’t have to take the risks a fresh transfer may produce; if the hormonal profile is not in the correct state, the transfer can take place during an alternative, natural or medicated, frozen cycle.
Another factor, which is thought to affect implantation, is blood flow and immunology. This is, currently, a rather controversial subject, in which many studies are taking place. Dr Izquierdo advises that the issue, with testing in this area, is that, as of yet, it’s difficult to produce any clear or fully conclusive results.
However, it is known that the implantation process requires good blood flow, to the uterus, so that the embryo can implant and continue its development, inside the endometrium. For women with recurrent implantation failure or miscarriage, Dr Izquierdo does recommend testing for thrombophilia (blood flow disorders), stating that, although limited, studies are being conducted, into blood flow, and data is showing that when embryo aneuploidy (embryo anomaly) is ruled out, thrombophilia could be to blame, for implantation failure.
There is also some controversy surrounding NK (Natural Killer) cells testing, but, again, Dr Izquierdo advises it’s worth testing in women with recurrent implantation failure and miscarriage.
NK cells are thought to kill the outer shell of the embryo, thus making implantation impossible. If a patient tests positive, for NK cells, then there are possible treatments, which can be suggested, to see whether the chances of implantation and ongoing pregnancy, can be improved.
Whilst embryo quality is the main factor responsible for implantation, it’s important to remember that it’s not the only determinant. Uterine and hormonal health is of great importance too and, whilst some tests may currently not be conclusive, more studies are taking place, and data is being collated, so that medical scientists can improve their knowledge and further understand how to help healthy embryos implant. Each patient is unique and personalised treatment truly does play a huge role in the final frontier, of IVF.
The thickness of the lining is mainly due to estrogen, so that means in the first part of the cycle. In fact, when we prepare the endometrium for egg donation or for embryo transfer, we look at the endometrium because it needs to be about six or seven millimeters only with estrogens. In fact, after estrogen therapy, when we include the progesterone in the cycle, it may even be thinner, but that’s not important. The main issue is the thickness before that. So, if the endometrium grows properly with the estrogen therapy this may be due to bad absorption of the medication or because there is a problem in the uterus, maybe adhesions, a septum or some other problem in the uterus that’s interfering with the endometrial growth, but not really with progesterone.
I think it’s crucial because otherwise, we won’t know what’s happening in your body, in the uterus, and what is interfering with the endometrium. If we have high estrogen levels, that may interfere with implantation. If estrogen rises very early during the cycle, this might have an impact on implantation. So, it is very important to measure both estrogen and progesterone. It’s true that it’s not worth measuring them at every check-up but at least at the beginning of the cycle and, of course, on the day of triggering. In the frozen cycle is it the same. We always need to check the estrogen and progesterone levels before we start progesterone administration to be sure that the progesterone levels are low before we start the external progesterone.
The biggest study showed this refers only to a lower implantation rate when we use estrogen tablets for more than 30 days or in administration without progesterone. If it’s only estrogen, we know the endometrium may not be well prepared for implantation. That can also explain an early miscarriage. If it’s too early, a biochemical pregnancy may explain this. It can happen because the endometrium is not really well prepared for pregnancy.
About 10 ng/ml is fine, so 60 is absolutely fine. We don’t have an upper threshold so even if we had a 100, that would also be fine. The only problem would be if it were very low.
There’s no upper threshold. There’s only a lower limit.
Both are important. If we have a triple line at four millimeters, it’s not enough, even though we have seen some pregnancies with that. The pattern is also important because you should have a triple line with six millimeters, but we’ve also seen pregnancies with some distorted patterns. What I would ask is why there is no triple-line pattern. The main thing, when we don’t see a triple-line pattern, is to perform a hysteroscopy to see what’s happening in the uterus, to see if there’s something interfering with the endometrial growth. If we see something, then we can correct it: if we don’t see anything, then there’s the possibility of doing a different type of protocol to see if the endometrium reacts differently. Unfortunately, we have many patients where we see an endometrium that’s not triple lined, but finally, some of them will get pregnant. We don’t have 100% certainty that it’s not going to work, but at least a hysteroscopy should be done.
In a natural cycle, that’s very difficult to say. There is no one single number. Basically, if the embryo is day 5, we’re talking about a blastocyst stage embryo. The best day for implantation in a natural cycle is 7 days after triggering, the ovulation. If we’re talking about a substituted cycle, then it’s on day 5 of progesterone, always starting progesterone on day 0. This means 6 days before. So, day 19 or 21 would depend on each individual cycle and the best way to control it is to assess ovulation, to induce ovulation artificially or to control it with LH Surge and then to decide when to do the transfer. It should be at least 7 days after LH Surge. In previous slides, there’s also the timing for spontaneous LH surge but I don’t really recommend it in an absolutely natural cycle because it’s very difficult and uncomfortable to test LH surge every 12 hours. LH surge is very difficult to control but if we can control it, it’s fine to do the embryo transfer 7 days after, but I cannot say if it’s 19 or 21 from the first day of the period.
That depends. Not all natural killer cells are bad. We do the diagnosis of natural killer cells and then we see the type of natural killer cells. That’s why the immunologist should follow the patient. Normally, when we have these problems and if they have had five failed IVFs it should be important to see the embryo quality in those 5 IVFs because she’s had three natural pregnancies with the own egg without any treatment, which is quite curious, and then three miscarriages. I think thrombophilia should be tested and if the natural killer cells are the bad ones, then a treatment should be encouraged with steroids to prevent NK cells.
Normally, we do blood, as there aren’t many labs that will do NK cell testing with an endometrial biopsy. The best thing would be to have both to have an accurate diagnosis but if this is not possible, then the blood tests alone would be fine to start treatment. As I said, there are many immunological treatments that may be used, such intralipids or immunoglobulins but that’s something for an immunologist should talk about because I don’t really think we have enough information to use them. Steroids are something we can control quite easily and we can use them when we see NK cells in the blood. We also have some tests with an endometrial biopsy that can talk about NK cells but we don’t have many labs that will do this and not many patients have the opportunity. If we have in NK cells in the endometrial biopsy we can also use ACG or steroids to prevent any implantation failure.
The main thing is that we normally need to have a diagnosis. If you’ve only had one embryo transfer, maybe it’s just bad luck that you didn’t get pregnant. It’s worth trying again. As for immunological issues, as I have said, it’s quite controversial. Normally you may find some doctor that won’t do the tests because it’s something that still needs a longer study to give us a good tool to use with our patients. If it doesn’t work a second time with egg donation and you’ve already had a pregnancy, why not try testing for endometrial receptivity or window of receptivity. Thrombophilia or immunology would also be an option. For the moment, if you’re taking these estrogens, Clexane and the progesterone that should be enough for second embryo transfer.
ERA testing is the one I was talking about in terms of the window of receptivity. We use it regularly with implantation failure and it consists on doing a substituted cycle with estrogens and NRP for about 15 to 20 days and then one week of progesterone administration five days later; as if we were going to do an embryo transfer at the blastocyst stage. The moment we take the biopsy, we send it to the lab and they tell us the endometrial genetic pattern that they obtain and whether we’re ready for implantation. In 90% of the test performed, patients are receptive. It’s not for everybody, but we tend to do it for those patients with implantation failure to assess the right moment. In those patients with implantation failures, we found many of them have had a problem with the window of implantation. We changed our protocols for embryo transfer and we have very good results with that.
I understand you mean the level in the blood and not the dose of medication. Estrogen levels should be more than 100 picograms/ml to be normal wrong and progesterone should be more than 10 picograms/ml on the day of the transfer to be sure that everything will be fine, but these may vary a lot. We have patients with 150 picograms/ml of estradiol and we have another one with 1000, so it’s very different from one patient to another in terms of absorption. The main thing is that it should be too low. With progesterone is the same: we don’t have an upper threshold but we have a lower limit of 10 picograms.
It’s very difficult after all these embryos failures. Most of these embryos would have been abnormal. When we have a genetic diagnosis but we don’t have implantation it is very difficult to explain but we see this, even when everything is perfect. Implantation is never 100% so maybe it was just bad luck that those embryos didn’t implant. Implantation should be around 70 to 80%, depending on embryo quality, and there are some things that PGS cannot test: the embryo quality itself, the potential of the embryo to implant, the energy that it has. It’s true that after 42-43 it’s very difficult to have a pregnancy with own eggs. If it fails, I know that it’s very difficult, but maybe donor egg would be an option. You could go down other routes such as immunology, but that’s not the main thing. As we said, the main thing is the embryo and if we don’t have a very good embryo, then other issues are not worth testing.
Polyps distort the endometrium, affect the cavity and of course, affect embryo transfer. If there’s a large polyp in the cavity they should remove it. It’s an easy technique and it helps implantation a lot.
The level is just on the limit: 9.5 to 10 is the lower limit for progesterone. It’s quite surprising that with 1200 milligrams it didn’t increase, so maybe the way of administration was not right. There’s a way of using subcutaneous or intramuscular progesterone to increase the level, so that could be an option. We know that when we use injections, progesterone blood levels increase a lot. Although a 3AA blastocyst is good, it’s not top quality, so maybe the implantation or the pregnancy chances were not 70%, the average pregnancy rate for egg donation embryos, but might have been 50%. Just in case, I would suggest having subcutaneous or intramuscular progesterone for the following cycle transfer.
There may be different explanations. The first thing to do is to be sure that the spotting comes from the uterus and not from the cervix, which sometimes happens. If it’s from the cervix then there’s no treatment, it’s something normal and we don’t need to treat it as it won’t affect implantation. If it comes from the endometrium, there are two possibilities: either there’s a problem with the lining, perhaps a small polyp they haven’t seen, an adhesion that may cause a change in the endometrium, or the endometrium is not receiving a good dose of medication; the hormones are not getting to the uterus. This would be easy to assess. A hysteroscopy would be recommended and then trying different protocols of endometrial preparation; different estrogen administration, oral, vaginal or subcutaneous; the same with the progesterone. We could also change the different medications to see what different reactions there are. Of course, check body nutrients.
Let’s imagine, with a day-3 embryo, we’re going to do the embryo transfer on Friday then you should start the progesterone on Tuesday morning, so, 4 days later.
Before treatment, we need to know what’s happening so and there are tests for blood flow. Many times we send our patients to a hematologist to check all the parameters for thrombophilia, just to be sure that we’re doing things well. There may be a reason unrelated to implantation, but if it is, there might be a treatment. The main thing is to see a specialist to be sure. The moment you start anticoagulant treatment, you should monitor it with blood tests to check the levels of anticoagulation and determine if you should stop the medication if you get pregnant or whether you should follow it during pregnancy. Before this, we need to have a diagnosis.
I would have to check with the European Union, but there should be no problem to transport embryos. It is important to check and what we tend to do is we talk with labs and then they have to check the different protocols to be sure that everything is compatible to give you the maximum chances for your transfer. Then, if the law permits the transport and the protocols are similar, it’s done. If the patient is based in Europe, this should not be a problem.
We don’t have experience with anti-histamine treatments. If it’s a treatment you’re doing for your own health, we know that sometimes it’s ok to take it during pregnancy. If that’s something they recommend it for the treatment, I have no idea. I haven’t seen any studies regarding this.
It’s very difficult to explain sometimes why it doesn’t work but it’s important to look at the preparation protocols and think about everything that happened before the embryo transfer. You should look carefully at the endometrial preparation, the endometrial pattern; also the window of receptivity may have altered, so we need to check this as well. And, of course, there is embryo quality. We know that egg donation is a very successful treatment, but apart from the egg donor, there may be a problem with the sperm, which may have an impact on embryo quality. It’s important to check everything.
We’re currently conducting a study on endometrial scratching to be able to focus on whether this technique really has a benefit for patients. It’s quite controversial and there are many studies which say it is beneficial, and others that say it’s not. Our studies are conducted with egg recipients to avoid any problem with embryos that may affect pregnancy rates. We’re seeing some differences and we hope we can publish something by the end of this year, to see which patients have a real benefit, but we think that there is no harm so if there’s a possibility, why not.
38 it’s not that old and AFC of 11 is not that bad. Maybe there are many other things to check before going to egg donation and end up with the same implantation failure problems. I would ask for other tests like haematology or immunology to try to improve ovarian stimulation to maximize the number of eggs and try a frozen embryo transfer with a genetic diagnosis if you have good blastocysts. Of course, going to blastocysts before starting the embryo transfer is absolutely crucial. Egg donation is always there as an option and you could try egg donation next year or in two years, but if you want to try with your own eggs, this is now. It is a very difficult issue and I would advise looking at other things and if everything is normal, try to do another cycle with your own eggs to see if you can get blastocysts.
This is not a legal issue and there is no legal limit in Spain, but we normally don’t do these treatments after 50, as with all clinics in Spain. However, this is not the law.
That depends on the size of the fibroids and on the location of the fibroids and cysts. If we have small fibroids and they’re not in contact with the cavity then there’s no need because if we remove a fibroid we’re going to leave a scar and that won’t help with implantation either. If we have a fibroid that’s just inside the uterus, just inside the cavity, or if it is very large, it’s better to remove it before going for a cycle. In terms of cysts, it depends on the type of cyst because there are endometrial cysts that can be removed if they’re very big. If there are small or functional cysts they might not have to be removed and might not actually increase the chance of pregnancy itself. Basically, depending on the size and on the nature of the fibroid or cyst, the doctor has to give you a recommendation according to the many publications in the literature.
It is possible so long as the law in Europe permits and if the freezing protocols are compatible between clinics. It’s always the lab that gets in contact with the recipient clinic and then we try to advise patients on what to do.
We could recommend ERA for everyone, but it’s a cost and we have to do a substituted cycle, so it really depends on whether you can plan for it. Maybe in the future, we will do this for every patient, but at the moment we try to do it only for those patients with implantation failures. If you’ve done those transfers, but with the bad quality embryo, maybe we’re not talking about implantation failure. We could check hormones but it’s not entirely necessary: it would be like having a headache, going to the emergency room and asking for a CAT scan. There’s no real medical indication. We don’t tend to do all the tests before cell cycle and if you don’t have a diagnosis of implantation failure, it shouldn’t be necessary.
Only if you were taking some medication that might interfere with pregnancy but I assume that this was not the case since you underwent treatment and got pregnant. The most likely explanation for this is that there was a problem either with the embryo or with implantation, but not with the depression.
We tend to do it about a week before we stop the Pill. The previous cycle to egg donation is done with the Pill to synchronize the egg donor and the recipient. Then, we stop the pill at a certain point to start the cycle. We do the scratch one week before that.
Embryo glue is a trademark of a specific liquid culture medium into which we put the embryos before we do the embryo transfer. It has a high hyaluronic acid content, which helps the embryo attach to the endometrium during the moment of transfer and helps with implantation. We tend to use a culture medium rich in hyaluronic acid for all embryo transfers because we think it might help. We used embryo glue for a while and, when we tested it, we found no differences in pregnancy rates. So for the moment, we try to use a conventional pre-transfer medium that contains hyaluronic acid, but it’s not specifically embryo glue. There are many different culture mediums that may do the same thing.
If it’s heterozygous mutation, it might be a cause; if it is homozygous, it’s less likely to be a cause. If it is there, and after all these failures, normally I think that any hematologist would recommend treatment for that. Of course, after all these implantation failures with these normal embryos, and regarding your age, there may not have been an impact on implantation, but it should be treated.
I don’t know about this medication described. I would have to look at it and answer by email.
That’s something that the embryologist should answer because it doesn’t depend only on the day; it depends on all the development of the embryo during the time they’ve been in the lab. It’s not the case that, during the first days one of them looks better or worse. They develop in different ways and with a different number of cells, so when we have doubts about day 5, we should look at the previous days. That’s something the embryologist should tell you.
I assume that’s the TSH level and if it’s 6.6, it’s very high and you should be on treatment to try to reduce it to less than 2.5. That’s the level tend to have or we tend to look for before pregnancy.
I think if you have an embryo, you should go for it. You never know if this is the one that’s going to give you the pregnancy, and you shouldn’t go ahead with a new cycle. I know it’s difficult sometimes when we have an embryo of a lower quality, but 4BB is a good embryo and I think you should go for it. You never know. Many embryos of different qualities implant, so it’s worth going for it.
Some studies say that it might improve egg quality, but it’s very difficult to say. It won’t be bad for egg quality and it won’t do any harm, but I’m not 100 % sure that it will improve egg quality. Be cautious with it and do not expect to find a 100% change.
We tend to look for less than 2.5, some obstetricians say less than 2. It also depends on the thyroid antibodies, but less than 2.5 is what we expect to have here.
It’s not 100% necessary, but some protocols do it to avoid any follicular growth during the procedure. We do the same with the donor and the recipient and the recipient may produce some follicles. The tiniest growth might produce hormones that interfere with the cycle. That’s why we give it, but it’s not 100% necessary.
It shouldn’t be a problem. Many patients come from different countries in Europe, come into the clinic in the morning, do the embryo transfer by midday and go back home in the afternoon or later that night. We would normally give some recommendations after embryo transfer, but activity can be continued as normal. Rest is not absolutely recommended.
It’s still okay to travel. The only thing is that, since patients will have had many hormones, sometimes we give an anticoagulant for the journey because it’s quite long and to avoid the risk of thrombosis. But that’s the only thing.
You can continue with your normal life. No need to rest.
That’s not a problem.
We recommend avoiding immersion for one week, but besides that, afterward, you can continue swimming as normal.
It is a bit low but it shouldn’t affect implantation as long as you live normally with it. If there’s a problem that has caused this low level, it needs to be diagnosed, but it shouldn’t be a cause of implantation failure.
Diet has no influence at all. Eat what you like; whatever makes you feel good. The days spent waiting for the blood pregnancy tests are very hard so no need to look at what you’re going to eat or drink. Of course, no alcohol and not too much coffee.
Gluten intolerance is an autoimmune disease that may increase inflammation in your body, so if you feel that you might be intolerant, avoid eating gluten during the period of treatment, and implantation should be fine. Just as ever, avoid doing any harm to your body that may affect your health in general, and this is also true for implantation.
On the question of the embryo quality, you should ask the embryologist about the whole development of the embryos, not only on day 5 but all previous development. This will tell you the quality of your embryos and then they can tell you which is the best option to get pregnant.