How to prepare for an embryo transfer to have better chances?

Tomas Frgala, PhD
Head Physician , UNICA Clinic – Brno

Embryo Implantation, Embryo Transfer

Dr. Tomas Frgala offers insights into preparing for frozen embryo transfer. The accompanying image portrays a smiling man wearing a white shirt.
From this video you will find out:
  • What is the definition of embryo transfer?
  • What are the phases of the endometrial cycle?
  • What is the ideal endometrial thickness?
  • Why is the blastocyst stage important?
  • How should I prepare for embryo transfer?
  • What are the steps to be taken on the day of the transfer?
  • How many embryos is it recommended to transfer?
  • What I should do after the embryo transfer?

How can I increase my chances of successful embryo transfer?

During this webinar session, Dr Tomáš Frgala, PhD, Head Physician at UNICA Clinic – Brno, started with short topics he’s been focusing on during his presentation. Dr Frgala explained the procedure itself and discussed the regimen after transfer. He started with two major characters, the endometrium and the uterine lining, in which we place the embryo and then the embryo itself, where the quality of both plays a crucial role in the process. Later on, he switched his focus to the patient and talked about the holistic approach and what can be done or supported throughout the process to increase the chances.

Embryo transfer – definition

One of many possible definitions of embryo transfer is the insertion of the selected embryo into the uterine cavity, but what makes it exciting, and kind of stressful, is the fact that this is usually the grand finale of the assisted reproduction treatment. The stimulation of the patient herself, fertilizing her own eggs with the sperm cells of the partner and the embryo transfer, then the following care or a cycle where donated eggs are fertilized. The embryo is transferred into the recipient’s uterus, where we have to prepare the endometrium, the uterine lining to the best of our knowledge or the third category, the frozen embryo transfer. We are not placing the embryo directly into the endometrium, but rather very gently and carefully between two layers of the uterine lining.

Endometrial growth – the process

The lining that we need to prepare for the embryo, so it has a good chance to go through the implantation process, start the communication with the mother’s organism and then develop further and prosper. Dr Frgala explained that the endometrium has to have a certain character, certain type and a certain height, this goes hand in hand with the natural process throughout the natural cycle when in the first half throughout the proliferative phase where usually the dominant follicle grows, it provides estrogen hormones and under the influence of the estrogen hormones the lining grows. We want it somewhere between 7 and 12 millimetres for the transfer, anything between 7 and 12 millimetres appears to be sufficient, anything between 8 and 10 might be labelled perfect, but it’s individual. Following the ovulation, around the midpoint of the cycle – day 14 where the ovulation happens. Following the ovulation, the follicle rebuilds and the cells of the follicle start to produce a second crucial hormone for the cycle, progesterone.

Under the influence of progesterone, the blood flow in the uterine lining increases, it becomes softer, a little wet, and it becomes perfectly ripe and ready for the embryo to nest. While the first phase and the effect of the oestrogens, the proliferative phase may vary in length, and we can play with it a little. Sometimes, it’s a little shorter than 14 days, sometimes it may be a little longer than that. The second phase, the secretory phase is very sensitive to the timing because following approximately 5 days of progesterone which is the standard, that’s the time when the endometrium is just right or where the implantation window opens up, and the lining is perfectly ready for the embryo.

There are still discussions going on whether that implantation window is quite short 24 hours, 36 hours or whether it’s much wider up to 4 days, we don’t exactly know, it can also vary from patient to patient. Around 2 days should be right, regardless of the procedure undertaken. We always check at least once, usually around the day 10 to 12, if the endometrium is growing, if it has the right structure and if it has the right thickness.

The importance of the blastocyst stage

The second major participant and seemingly the most important one is the embryo and its quality. The embryo usually develops for 5 days in the lab, and throughout this embryogenesis, it should actually divide, then compact, and then eventually develop into the blastocyst stage. There are various blastocyst stages, all of them are fine for day-5, an early blastocyst, blastocyst, expanded blastocyst or a hatching blastocyst. There is still a discussion on the point of embryo development, it is perfect for the transfer. Usually, it’s one of the two variants, either day-3 of the development or day-5 of the development.

Nowadays, most clinics move towards day-5 for the embryo transfer, at Unica, we do the same thing because we feel that way we can learn a lot more about the embryo until day-3 at least, that’s what one of the embryological hypotheses says, the embryo develops mainly from whatever the egg brings to the cooperation. From day-4, it’s about the quality of the genome from both gametes, from both sides, that starts to show. Also, that’s the phase where many embryos stop their development. We feel that if we transfer on day-5, we give a chance to the truly viable embryos, that’s the time we pick for transfer and cryopreservation of the other embryos.

It doesn’t mean day-3 embryo transfer would be wrong, but that’s just a clinic preference, and day-5 is our preference and has been for quite a long time. There’s always an argument saying if you insert the embryo on day-3, you’re putting it in the uterine cavity, the best incubator for the embryo there is. However, if you look at it from a different angle, you might say that the embryo, while it develops, is moved through the fallopian tube and enters the uterine cavity towards the end of day-4 or at the beginning of day-5. Somewhere around that time, so around day-3, it’s still in the fallopian tube, it’s not in the uterine cavity. Either way, it’s fine, and the success rates are comparable.

Preparing for the embryo transfer

The next thing that Dr Frgala focused on was the preparation of the patient. Dr Frgala emphasized that preparation is not only about the technicalities, such as the quality or height of the endometrium, the quality, and viability of the embryo, and the patient state of body and mind.

This is where it gets tricky, and this is where it gets somewhat difficult sometimes, it’s also individual, it’s different for every patient. Everybody needs something else, some patients prefer their usual regime, they go to work as if nothing serious was going on and then just stop by for the transfer and continue saying, if I focus too much on this, I’m going to go crazy, this did happen to me in the previous cycle I don’t want to think about what’s going on right now.
On the other hand, many patients prefer to slow down a little, take some time off, we try to discuss it with them, support them and offer options that might lead them towards the more holistic approach, such as yoga instructors, acupuncturists, nutrition specialists, there’s a psychologist.
We don’t force these on everybody, but there are options that the patient can choose individually, one or the other or a combination, just to see what works for her best. It’s not just a question of the patient, and all the members of the support team, but also her family, friends. Someone doesn’t like to reveal that much to their surroundings, somebody else likes to share, once again, this is individual, there is no right way to do that. There is no procedure that we would force or could force on anybody, we just need to listen, we need to try to adjust, and as we go, we need to tailor sort of the approach and the whole preparation to the needs of the specific patient. The patient’s coordinator plays a very important role in that, and her physician as well.

Acupuncture before the transfer

One of the most popular approaches as a part of a holistic approach or the methodology is acupuncture. Once again, there is no right way to do that. There is no guideline or regime that we would dictate or even recommend. If I were to pick, I would probably go for at least 1 session a week throughout the transfer cycle and the transfer itself. It’s usually timed around day 20-21 of the cycle, so that gives you 3 sessions, maybe more. We are also able to provide an acupuncturist on the day of transfer at the clinic. The patient can have a 20-minute session immediately before the transfer and then once again immediately after the transfer if she wishes to do so.

Dr Frgala once again reassured that it is about the team effort even though the patient herself plays the major role, she shouldn’t feel that all the responsibility is on her shoulders. Everybody plays a role, and ultimately we always need a little luck, we always need a little help from nature herself.

I just feel heartbroken when the patients ask me what have I done wrong, and maybe I shouldn’t have done this. I always say you have done nothing wrong and nobody else there, maybe the embryos weren’t viable enough, or we just were not lucky enough, but if we keep trying, we usually and a very high percentage of patients persevere and reach the goal.

Cutting-edge technologies

There are some very interesting technologies as well being used throughout the process. Embryoscope or generally so-called time-lapse technique where the embryos are cultivated individually in wells and each well has a camera, and that camera takes a picture every 10 minutes in infrared light as not to disturb the embryo. These pictures are lined up in the computer, and the embryologist can follow the embryo throughout its whole development without ever having to manipulate it, without ever touching it. There are still discussions going on at the meetings about whether Embryoscope or time-lapse technique is the future of embryo selection or just a luxurious cultivation box. We might not have all the answers just yet, but according to Dr Frgala, even if it is just the luxurious incubation box, let’s go for it, the embryo deserves it, and the embryo appreciates it.

Another thing is PGT-A and PGT-M testing. The pre-implantation genetic testing for aneuploidies previously called genetic screening (PGS). Another test is called PGT-M, the pre-implementation genetic testing for monogenic diseases where there’s a specific problem that we’re looking for. These are also being discussed and argued about. There are situations where they’re very helpful, there are situations where their use might be less important or even questionable. It’s always best to talk to your specialists and get through the consult. It’s important to try to be quite open, even if, in some cases, there are no clear-cut answers yet, but that’s a very interesting direction.

EmbryoGlue is one of the methods that we still collect the data. The studies are still coming in, which are supposed to show whether it has a strong significant effect on the embryo’s chances to nest or if it’s just a marginal method. We’ll see, but it looks promising, it doesn’t hurt. It’s a cultivation medium with growth factors and other goodies for the embryo. It’s cultivated for several minutes, 15-20 minutes before the transfer and then it’s taken with this media and transferred like droplets with microliters of the media into the uterine cavity.

Embryo transfer – steps

1. Come to the clinic with a full bladder

Whenever the transfer is performed under the control of the ultrasound, a patient should come with a full bladder because then it’s easier to see on the ultrasound. Plus, if we look from the side, the uterus kinds of bent forward, in the so-called anteversion, and the bladder is right underneath the body of the uterus. Getting through this curve with the catheter is not always easy, however, with the full bladder, the body of the uterus gets lifted, and the way for the catheter is straight and then makes it easier.

2. The doctor will insert the embryo into your uterus through a soft, thin catheter.

It’s not actually that easy but it’s not that problematic of a procedure, it’s not painful, you don’t need to worry about it, anaesthesia is not necessary. We always perform it under the control or the guidance of the ultrasound and usually in 2 steps to keep it most comfortable and quick for the embryo. At first, we just take the cover of the catheter with a thin probe, and it has a memory effect, so if the uterus is shaped in a let’s say less than the typical way, we can point it in the right direction, watching it on the ultrasound. We go into the right depth, and when everything is set and perfectly ready, only then do we call for the actual soft catheter, and they bring it with the embryo from the lab, and the catheter just slides through that cover into the uterine cavity. The procedure takes just seconds, and it’s comfortable.

Dr Frgala added that it’s better not to use any deodorant or any strong soaps on the day of transfer, it’s only because the embryo is brought in an open catheter, and the molecules of like the strong smell might be a little aggressive to the embryo. There should be no smoking before the transfer but also no intense perfume. After the transfer, you can do anything you want, and it’s not going to have any effect on the embryo anymore, this is only a question of the moment where they bring the embryo in the catheter.

How many embryos to transfer?

This could be a whole lecture and a very interesting topic, but the short answer to this question is just one. It’s been over 10 years when even the legislature in The Czech Republic was adjusted to motivate the couples to transfer just 1 embryo, the procedures, the success rates have been going up, and what used to be a necessity to put more embryos in to increase to support the chances, it’s just not only not necessary anymore, it becomes irresponsible and risky. Multiple pregnancies carry more risk for the woman, and the babies, who are often born prematurely and stress the whole family. A twin pregnancy should not be the goal of the treatment, specifically not in cycles with egg donation because the success rates there are around 60%, and if you transfer 2 embryos, you increase your chances only very slightly, but the risk of multiple pregnancies is significant, 45% of couples with two embryos used to end up with twins.

The couple does have the right to decide if 1 or 2 embryos are transferred. Unless there’s a contraindication such as a scar on the uterus, for instance, C-section, then 1 embryo is recommended. There are exceptions, when there’s a woman over 40, and she’s doing a cycle with her own eggs, the chances are very low, so sometimes we agree with 2 embryos. In The United States, they still transfer 3 embryos sometimes just to increase the chances in these specific situations, but generally, 1 embryo per transfer should be the decision, and that’s our recommendation.

How long does the actual transfer take? For the embryo, it is just a couple of seconds, for the patient, the physician, a couple of minutes. The complete visit to the clinic, including everything, the preparation, the paperwork, etc., takes about 30 to 60 minutes, and it doesn’t hurt.

After embryo transfer

After the transfer, we recommend a normal regime, normal activity. Bed rest is not necessary, it’s not forbidden, but studies were showing that the length of bed rest after the transfer does not have any major or any influence at all on the success rates, so it’s not necessary. We recommend taking it a little easy for the 7 days after the transfer and refrain from heavy physical strains, so no heavy lifting, no sports and no sexual intercourse for about 7 days.

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- Questions and Answers

Is it better to transfer 1 or 2 frozen embryos on day-5?

It depends on what cycle the embryos are coming from. If they have been frozen as a part of the stimulation of a 43-year-old woman, then I wouldn’t argue, and I would be comfortable transferring 2 embryos. In the group aged 40-45, the chances are 1- 5%, so that’s very low. Otherwise, in all other cycles in younger patients with their own eggs or with egg donation, I would opt for 1 embryo, but it’s always good to discuss and individualize because the history of the patient is important, several previous cycles, the quality or the stage of the embryos, all of these things can play a role during that decision process. Generally, 1 embryo per transfer is the recommendation.

I have read that frozen embryo transfer (FET) has a higher success rate where down-regulation is not part of the protocol. What are your thoughts on this? Is the age at the time of transfer relevant to this?

There are two ways to prepare the endometrium in the frozen embryo transfer process. Either we build the endometrium up with estrogen pills, and then at the right time, we step in with the progesterone pills at the time of transfer, the advantage is we have it under our control. We can increase the dose, we can prolong the initial phase and play with it a little more. Also, the timing is more flexible. There’s another way, and that’s the so-called natural cycle, or just to be an accurate modified natural cycle. The truly natural cycle is logistically quite straining, you usually have to take blood tests every day or every other day, follow the dominant follicle very closely because you don’t want to let it rupture unobserved. Therefore, typically, we modify it, which means we start with a natural cycle, we check it with ultrasound around day 10-12, and when there’s a good dominant follicle of the right size, say 17 through 20 millimetres, and the lining has the right structure and the right height, we step in, we’re using an HCG injection with time the ovulation and then build up a protocol from there. Typically, just applying progesterone for extra support, but even that’s not necessary if the follicle is nicely grown, if it’s sufficient, we may just perform a blood test for progesterone on the day of the transfer to see if the patient has enough progesterone of her own. The success rates of both of these preparations are comparable but at our clinic but not only at our clinic I have heard these from colleagues from France, Germany, Spain, the success rates with the natural cycle are typically a little higher. The difference is statistically insignificant. Both of them are fine, but we do like the natural cycle. There’s one condition, the patient should have a fairly regular cycle which typically represents reliable folliculogenesis, the dominant follicle should be there to provide the hormones for the endometrium to grow. There have been 3 studies that have shown that the natural cycle or the native frozen embryo transfer cycle or generally a cycle where there is a yellow corpuscle meaning the dominant follicle ruptures that might be leading towards an easier pregnancy with lower risks. I’m sure further studies will be needed, but the native frozen embryo transfer cycle is quite popular, and it would be my first choice in most of the patients. We have used down-regulation with the GnRH analogues to kind of put the whole system of the patient to sleep and then start the preparation. We have been using antagonists. Starting the preparation first and then blocking the own hormones of the patient. Eventually, we have abandoned all of these because these medications are rather costly, and we also have learned and confirmed many times that the regular dose of oestrogens that we give in the hormone prepared frozen embryo cycles and that’s 6 milligrams of estradiol per day from day 2 of the cycle, that dose of estrogen in itself usually serves as a down-regulation. We don’t use it, I haven’t read any studies, and I cannot comment on whether the success rates with the down-regulation would be lower, but I have many other arguments to support the simpler approach, the native transfer or the native cycle transfer or the estrogen prepared cycle without any further preparation or down-regulation.

What is your opinion about endometrium lining? Should it be trilaminar before transfer?

Optimally, yes, that’s one of the characteristics we’re looking for. It should be trilaminar before the ovulation happens, or before the progesterone is added to the protocol. Once the progesterone starts its effect, the blood flow increases and the endometrium automatically changes its structure. It is visible on ultrasound, it becomes a so-called hyperechogenic sort of whitish, and the trilaminar structure is not observed anymore. Throughout the initial phase, the proliferative phase, yes, optimally it should be trilaminar, however, we shouldn’t get too fixated on that because the echogenicity is different in all women. Sometimes, it’s hard to see it, it depends on the machine, the setup of the ultrasound, the experience of the physician performing the examination. Even the studies can be tricky. There’s one lecture saying the character of the endometrium, the height is very important, then there’s the next lecture and the next study where they say the character or the look of the lining is completely unimportant, the height is not important. We’re still getting data, we’re still struggling with this, but yes, trilaminar is optimal before the progesterone.

What types of tests would you most recommend before the transfer? DNA fragmentation of sperm and karyotyping? Or biopsy and immunology test of the uterine? When working with egg donation, is it more important to test the endometrium, sperm or in the optimum case, would you test both?

I wouldn’t necessarily think about these tests at the very beginning of the treatment, but if there’s poor development of the embryos, the quality of the sperm cell might play a role. If there are early miscarriages, that’s the same issue, so that’s where the DNA fragmentation exam might give us a certain point and what to focus on in the next cycle. Possibly using MACS (Magnetic Activated Cell Sorting) method for the sperm selection, for the fertilization during which the sperm cells with the DNA fragmentations are removed from the sample. Karyotyping would be a big discussion and not my first choice. The biopsy and immunology tests is a very modern approach. We used to analyse the NK (natural killer cells) specifically in blood at first, and if they were increased, we immunomodulated the patient, we suppressed their immune response. Now, there is this other test where we don’t measure the NK cells in the bloodstream, we measure them in the endometrium itself. A biopsy is performed, and the immunology tests. If the NK cell levels are elevated, then I would listen to the immunologist if he or she suggested an immunomodulation therapy, it could be a corticoid pill as a part of the transfer cycle, an intralipid infusion or immunoglobulin infusion, although those are not very popular because they’re extremely expensive. However, we still have to wait and see what the data eventually will show, how valuable these tests are. I had a very interesting presentation from Professor Jan Brosens from Great Britain at the last ESHRE meeting last year, where one patient did this immunology test in 4 subsequent cycles. One cycle after another, it just so happened that they did the biopsy 4 times, and in every cycle, the NK cell levels were different. Therefore, the question is how reliable is this examination. We should individualize, and if there’s been a couple of cycles without any success, I would look at both the endometrium and the sperm cells, both of these are amongst the basics of the preparation and the examination of the couple.

Would it be worth testing uterine NK cell level if the level in blood isn’t high?

That’s the tricky one, we don’t know. There’s a reproductive immunology specialist in the Czech Republic whom I respect and admire very much, she’s very well-informed, and I did have a chance to talk to her over the phone not long ago, and she published an article about the NK cell levels in the bloodstream and the immunomodulation and the improved success rates last year. When I talked to her after the ESHRE meeting, it was like half a year after the publication was published, she said don’t even remind me of that because I don’t know if that’s valuable anymore. Now, the focus has shifted towards the endometrium. I have to say the NK cell levels in the blood, we still measure them, and if they’re elevated we still talk with the immunologist and try to get advice or recommendation and maybe use a little immunomodulation if it seems necessary. The endometrium seems to be more interesting, but we have to be careful because there have been many presentations at the latest meetings saying, be careful the NK cells are helpful, they play a certain specific role during the implantation process of the embryo. You shouldn’t just wipe them out completely, you only have to use the immunomodulation where it’s necessary for the patient and finding out which patient that is, is very tricky.

I have a lot of feeling inside my uterus, I can feel the catheter as it passes through my cervix and even when it’s inside my uterus. This has made IUI and a dummy embryo transfer quite painful. Luckily, the procedure is quick enough for me to be able to tolerate the pain and not need sedation or anything. Does this have any meaning or implications for how things may go? Is it a sign something is wrong, or I won’t manage a pregnancy if it feels like this?

I think it would require further examination to answer this perfectly. Possibly, hysteroscopy might help where they dilate the cervix a little and insert a very thin cable with the camera looking in the uterine cavity to see if there are any atypical shapes. The dilation of the cervical canal itself might help. It has been written that when the uterus needs to be handled with extra instruments pulled or if it’s really painful that it might react, and that might be derogatory for the success of the procedure, but usually, this isn’t a significant difference. A little pain like this or unpleasant feelings during the procedure don’t pre-determine the patient to a lack of success. Some examinations might be performed to look for the reason or make it a little easier. Generally, this shouldn’t lower the patient’s chances significantly, but if you ask 5 doctors, you’re going to get 5 different answers.

Is a blood test to check progesterone level before transfer helpful to understand the best implantation window? When should this test take place, and what is the optimum progesterone level? Is progesterone level in the endometrium different from the level in the blood?

For years, I’ve been bothering endocrinologists and specialists at the meetings with the question of what progesterone level is right at what time. The progesterone level in the endometrium might be different from the one in the blood. No one truly knows because you cannot measure progesterone. Various application roots, injections, suppositories pills, they may be present in the circulation in different forms. Throughout the day, progesterone is produced phasically, it depends on when you perform the blood test. It was thought it doesn’t make sense to measure progesterone for a long time. Nowadays, there are two situations where it might be helpful, and that’s one shortly before the oocyte pickup or starting the progesterone in the frozen embryo transfer cycle, you want to see that throughout the first half of the cycle, that preparation, proliferative phase that the progesterone level is low. Then the second time, when we like to measure it, sometimes is on the day of embryo transfer. There have been some very interesting studies from Spain, from colleagues Dr Ernesto Bosch and Dr Elena Labarta last year, and they have shown that there is a cut-off in the progesterone levels on the day of transfer. If you don’t reach that level, your chances will drop. However, if you supply more progesterone and fix that lack of progesterone, you will return the chances to the right level. My answer would be the progesterone doesn’t necessarily have to be measured in every cycle but it might be helpful to measure it before the ovulation or the onset of the progesterone generally and on the day of the transfer. However, I don’t think it is very helpful, and it should be used as a way of timing the implantation window. I think that we’re not there yet.

I have done NGS in the past, but I’m considering a cheaper type of PGS with fresh transfer. However, it doesn’t check for as many chromosomal abnormalities. Those additional chromosomal abnormalities are checked with NGS, how common are those? Will I cover the most common chromosome abnormalities with regular PGS?

Normally, with regular PGS, the most common one, perhaps yes. I’m going to be blunt, and possibly many colleagues if they hear this will argue with me, but I would say NGS, although there are very fiery discussions about how reliable the methodology is. The older method, and here we’re talking about the FISH method, where a blastomere was taken from the embryo on day-3 and analysed until day-5, so a fresh transfer was still possible in the cycle. That methodology has pretty much been abandoned, it has been labelled a historical mistake. In comparison with NGS, it has been shown that embryos that have been labelled with the FISH staining method as pathological had turned out to have euploid day-5 embryos. Also, the blastomere biopsy on day-3 lowered the success rates of the embryos in the studies. I wouldn’t recommend that method, and I wouldn’t use it, I wouldn’t go for the regular PGS as it’s labelled here.

What is your maximum progesterone level before oocyte pickup to do a fresh transfer, and what is the minimum progesterone level in frozen embryo transfer?

Before oocyte pickup, it should be lower than 1.5 nanograms per millilitre. Some sources say lower than 1.5, some authors, more strict ones say, the progesterone should be lower than 1 nanogram per millilitre before the oocyte pickup. It should be 1 or 1.5 at the most. The second part of the question is about the minimum progesterone level in frozen embryo transfer. The Spanish studies from Dr Bosch and Dr Labarta showed the cut-off was 8.8 nanograms per millilitre, and in the other study, I think it was 9.2 nanograms per millilitre. We use a cut-off of 10 nanograms per millilitre if, on the day of embryo transfer, the progesterone level is 10 or higher nanograms per millilitre, we say that’s sufficient. If it’s lower, we add another form of progesterone, for instance, if the patient is already applying 800 milligrams of progesterone vaginally, one suppository in the morning, one suppository in the evening 400 milligrams each. Then we add an injection of subcutaneous injection to get the level of progesterone over 10 nanograms per millilitre. To sum up, it should be lower than 1 nanogram per millilitre before the pickup and higher than 10 nanograms per millilitre on the day of transfer.

Some clinics check progesterone levels repeatedly after the transfer until the HCG testing, and then continuously after positive pregnancy for several weeks. Do you feel this is justified?

That’s tough to answer. On one hand, it never hurts to know, you want to know as much as possible. For instance, we measure it on the day of transfer, and if it’s too low, then we compensate and then maybe measure again one more time a couple of days later, but not regularly. If this should be performed until the HCG testing? That’s two weeks after the transfer, that’s not that long, so yes, if there are 1 or 2 or 3 blood tests for progesterone, why not, but I know that most of our patients travel from abroad, they wouldn’t come back to us for that. Sometimes they go to their own gynaecologist, and they ask themselves for this. There’s still the issue of the reliability of the progesterone monitoring. I would say that it’s not necessary, but it doesn’t hurt, however after the HCG testing, I probably wouldn’t do it anymore, and I wouldn’t do it after week 8 of the pregnancy because that’s where the placenta takes over and the supplementation of the progesterone is questionable.

I had assumed the thickness of the endometrium lining was the width, is it the height?

If you look at the uterus, it has this pair shape, and the width would be from one corner to the other corner, which is usually 3-5 centimetres, and the depth is usually somewhere around 5-7 centimetres. It’s only when you look at the uterus from the side that it shows you the height of the lining. I wouldn’t call this the width. Every gynaecologist knows that it depends on how you set the probe, and if you cut the uterus like this and like the main axis, then you’re kind of looking at it from the side, and it doesn’t matter if you call it the height or the width. You’re looking at 7, 8, 9 millimetres, and that’s what you’re evaluating, so it’s just wordplay.

I am 39 years old, after miscarriage (week 10) would it be better to stimulate the ovaries in a couple of months and try to get more eggs, or go straight to frozen embryo transfer?

It depends on the other circumstances. Either way, it can have its advantages and disadvantages. If the frozen embryos are of top quality and they have a good chance of implantation, then the frozen embryo transfer is not going to set you back that long, it can be performed in about 2 months, so it’s not like you’re losing years, it can take up to 6 months. On the other hand, we do have patients who, for instance, are nearing the limit of the insurance company where the insurance still covers at least part of the costs, and if that’s the case, any insurance company in the Czech Republic don’t pay anything for the frozen embryo transfer. In that case, we sometimes keep the frozen embryos in the cryobank, and we stimulate them again as long as there’s that financial support. Another situation where there’s endometriosis, and then there are risks that it might progress and the patient might lose the ovaries, or if there’s a low ovarian reserve, then in 6-8 months, the ovaries won’t react anymore. In these situations, it might be a good idea to stimulate again and create more embryos, keep them in the cryobank and save the transfers for later because the age of the uterus is not that crucial for the success, it’s the age of the eggs that makes the difference.

Is it possible the steroids, Prednisolone or Hydroxychloroquine could affect the level of progesterone? What else can influence progesterone level? Is it a good practice to check transfer it on the transfer day, and if it is low, add an injection?

I have to admit I don’t know if the steroids like Prednisolone affect the progesterone levels, I don’t think. What else can influence the progesterone level? The type of progesterone that you’re taking, the time of the day, perhaps other things that I haven’t heard about, but I honestly have to say, I don’t know. Is it a good practice to check on transfer day? It’s fairly new, it’s been done for about a year now, and it’s still not a recommended part of the procedure. You wouldn’t find it in the guidelines, but I know that more and more clinics do that, following the example of our Spanish colleagues who found some interesting data in their studies. We don’t do it for every patient, but for patients who have their first transfer without success, we’re trying to look for all the details that might influence the embryo implantation in the second transfer cycle, therefore we check it on the day of transfer. I’m not sure if it’s going to be labelled good practice in the future, but I know it’s getting more and more popular. The injection is a good choice if the patient is already applying vaginal progesterone, it has been suggested that giving more vaginal progesterone might not be as effective, you might want to add a different form of progesterone, so injection is a very good suggestion.

I have been taking multiple supplements while trying to conceive, such as DHEA, Vitamin D, C, E Ubiquinol, NAC, PQQ, Fish Oil, Acai, etc. Is it safe to continue these up to transfer day?

I don’t think that they would have a negative effect. However, I do recommend my patients, if they take similar vitamins or supplements, to stop them the day before transfer. It might be the time for them to metabolize, it might be different in each one of these, so if you wanted to be sure that you’re going to be clean of these at the time of the frozen embryo transfer, you might want to stop a couple of days earlier. I usually say until transfer, yes, after transfer, no. I believe that it is safe, but I have no proof, I don’t have the data on these, but most of these are supposed to help, and they shouldn’t hurt the embryo, but I don’t know. I have to admit, I haven’t read any studies specifically on Acai or Fish Oil.

How many weeks of pregnancy do you recommend stopping the progesterone injections (Ingesta, Oxy or similar) while still taking the progesterone vaginal pill 800 mg per day? I was told to quit in week 6 of pregnancy, and I wonder if that’s why I miscarried.

For the last sentence, I have to use that FBI phrase from the TV series, we can neither confirm nor deny that you have miscarried because of this. I don’t think that was the reason, no if you have been applying progesterone vaginally 800 milligrams per day, that’s quite a high dose. If the injections had been necessary, on top of that, I would stop these injections based on what the progesterone level was before or it was given at all. I do believe that week 8 should be safe to stop these injections, but if they have been added to the protocol just to make sure and then they were stopped maybe around the time of the HCG test, but you continued taking it vaginally, it should take care of it. I don’t think that was the reason you miscarried.

Do you recommend PGT-A/PGT-M testing while using egg donors? Is it useful if the sperm has 1% morphology? And, if we do DNA fragmentation karyotyping, does that eliminate the need for PGT-A testing?

For the first question, my answer would be quite clear, you would get different answers from different colleagues, but I would say with egg donors, it’s unnecessary. I have seen it in other lectures, I have heard it from my colleagues, I have seen the studies, and on one hand, even in the young woman 22-23 years of age, approximately 20% of the eggs are aneuploid, so chromosomally challenged. However, I wouldn’t do the testing. PGT-M testing for monogenic disease would only be performed when you’re looking for a specific problem. That would have to be a situation where perhaps the gentleman was the issue because the donor has to be clean, an egg donor cannot be even a healthy carrier of any mutations. In such a situation, PGT-M might be discussed. I wouldn’t do PGT-A as the screening test. 1% morphology in the sperm cells, fragmentation karyotyping, it does not eliminate the need for PGT-A unless it shows quite a favourable result. If it’s not that bad, then you might say we don’t need PGT-A. If it’s bad and there’s a risk that the embryos will suffer through that, then maybe you might want to think about PGT-A, but I wouldn’t rush with that. Perhaps a sperm selection method such as MACS might be helpful if the DNA fragmentation is a little higher, then it helps to eliminate these sorts of poor quality or apoptosis pre-programmed sperm cells. These are rather complex questions, and we would have to know each other better and talk a little more to get to the core of this.

I’m 42, and I will be transferring my own embryos. Is there any negative impact of transferring embryos at a different stage of blastocyst development, i.e. a full blastocyst and an early blastocyst? Secondly, is there any negative impact of transferring embryos created during 2 different stimulation cycles?

I’m afraid I don’t have an easy answer for that. The embryologists used to say about 10 years ago that if you transfer 2 embryos, they support each other. Nowadays, it’s rather the opposite. Professor Macklin from Great Britain has been working on some very interesting experiments showing that the endometrium approaches a healthy embryo proactively, it stays away from an embryo that is not euploid or healthy. The situation where 1 of the embryos is a hatching blastocyst and 1 of them is just an early blastocyst doesn’t tell you that one of them is healthy and the other 1 is not. It just tells you that 1 of them is faster and the other 1 a little slower, but that’s not the ultimate parameter. Genetic testing sometimes shows that the fastest embryos don’t necessarily have to be the best. I wouldn’t have a problem transferring these 2 embryos at the same time. Transferring embryos created during two different cycles as long as the gametes were from the same partners, and if the embryos are of about the same stage, I would be comfortable transferring both at the same time. I would love to share another very interesting study from Spain. A different team had patients with repeatedly unsuccessful attempts, they had cryopreserved embryos from different cycles, and some of these embryos were frozen on day-3 and some of them on day-5. Once again, this was a question of the implantation window. They prepared the endometrium with progesterone for 4 days, then transferred on day 4 both of these embryos at the same time, the day-3 embryo and the day-5 embryo, and they surprisingly were successful. They got multiple cases where the patient was carrying twins, so both of the embryos implanted, both the 3-day embryo and the 5-day embryo from different cycles on day four. It puts a different perspective on the implantation window once again, and I think that just judging by this, you can comfortably say it shouldn’t matter that they are from the two different cycles.

I’m 48, my endometrium was 5.5 at day 12 and increased to 8mm at day 18, but no layering. I was taking 8mg estrogen orally and 2 mg vaginally, plus Sildenafil 100mg. Will that impact fetal development if implantation is successful?

At 48, it can be tricky 5.5 that’s low, 8 mm is better. If I wasn’t sure about the endometrium structure, then maybe I’d uh draw a blood sample for progesterone, just to see that the progesterone is lower than 1.5 or 1 nanograms per millilitre. In that case, I wouldn’t worry about that layering so much anymore because what makes us nervous is when the triple line structure is not there anymore, it’s hyperechogenic which might represent past ovulation. However, with this dose of estrogen, I wouldn’t expect ovulation and if the progesterone was low and the endometrium 8 mm, I’d say go for the transfer because at that age, it’s going to be tough to get better endometrium and better height. It shouldn’t impact fetal development. Anything between 7 and 10 should be all right, but it’s tougher as the age advances to build up a nice high endometrium of the right structure, but I would measure the progesterone if it was low, then I would go for the transfer.

My progesterone level the day before fresh transfer was 290 nmol. Would this impact the implantation of the embryo? How soon should it drop after, and to what level?

Anything about progesterone is always a head-scratcher. This admittedly is quite a high level. We’re dealing with nanomole per litre, and it’s almost 300, so as I said, you have to divide by 3 to get nanograms per millilitre, so we’re still looking at like 97-98 nanograms per millilitre, which is quite high. When looking at studies commenting on progesterone, I have to admit it did find studies that have said it should be at least 8, at least 9, at least 20, if it’s over 20 it’s better, the results are great. Then I have found a study that said if it’s over 20 the success rates drop, so it’s bad, but this was kind of an exception, an outlier, and I wouldn’t worry about it that much. I don’t think this should impact the implantation, but I don’t have any reliable data, I couldn’t find it in the literature. There was just this one study that said if it’s higher than 20 nanograms per millilitre, it’s bad, but all the others said it’s good for the implantation. I don’t think it should impact the implantation negatively. How soon should it drop after the transfer? It also depends on if you’re going to take any progesterone or not. If I had a patient with this progesterone level, I probably wouldn’t add any luteal support. However, if you’re talking about the fresh transfer, it also depends on what kind of protocol was used, a long protocol where everything is down-regulated, antagonistic protocol maybe, I would just lower the dose of progesterone and check again, in let’s say 3-5 days. Generally, I don’t believe that this should have a negative effect.
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Tomas Frgala, PhD

Tomas Frgala, PhD

Dr Tomas Frgala is a specialist in the field of Reproductive Medicine with an exhaustive experience of over 20 years. During his work at the University of Southern California, he participated in numerous projects and studies focusing on research on new substances in tumorous disease treatment. Recently, he has engaged himself in the research on new methods in the field of Assisted Reproduction. He is the Head Physician at UNICA Brno clinic.
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Caroline Kulczycka

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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