In this session, Patrícia Carvalho, IVF Nurse at Ferticentro, Portugal, has discussed elective single embryo transfer, why it is recommended, what are the advantages, if there are any disadvantages and success rates.
Patricia Carvalho talks about the decision to do an elective single embryo transfer, the pros and cons, and the most recommendations for many patient groups.
Patricia starts by showing a chart which is a study from the European Society. Here it shows the difference of the results when transferring one, two, or more embryos.
It can be seen that when transferring one embryo, the rate of having one child (one baby) is 90%, when transferring two embryos, the chances of having twins go from 2% to 41 that has 20 plus times.
Something important to notice is that when transferring three or four embryos, the chances of having twins don’t increase, so it’s pretty much the same. The point is that, probably, there’s not too much of an advantage of transferring three or four embryos because the rates of having twins are pretty much the same.
Moreover, when transferring two or more embryos, it has increased the rate of births of twins and has an impact in the society. The first IVF was in 1978, so the majority of the IVF treatments were starting to be made in the late 90s.
In the chart, if the rate of having twins of two pregnancies would have been naturally, it would be around 80,000 annual twin pregnancy shown in the blue bars. Therefore, because of the IVF treatment, nowadays, it’s higher than 120,000 a year.
According to Patricia, there’s always a romantic version of having twins because couples think that you have an instant family, straight away, so you don’t need to think about having a second pregnancy and that having twins is very cute, dressing them the same. This kind of thought is connected mentally, but it also has an impact on society, and financially in the families.
As seen in the first chart, the number of twins is directly related to the number of transferred embryos. In the past years, Patricia has seen some changes, and this is due to the decision to transfer one, two, or more embryos.
In this following chart, the study made by the European Society about human reproduction with data from 2013 related to embryo transfers from 1997 to 2013. This shows that, at the beginning, there were still some transfers with four embryos, but then this decreased very quickly because there was no shown evidence that there was some kind of profit or any good result, better than transferring three.
The red line shows that, at the start, transferring three embryos, the rate was even higher than transferring two. However, there was also a change where the tests, the positive pregnancies, and the rates of twins weren’t any higher than deciding the transfer of two embryos.
The blue line demonstrates that there were more and more couples deciding to transfer only one embryo because of a lot of reasons. Even though the number of embryo transfers, when transferring two, has increased which can be seen in the eccentric curve, is now stabilizing. This is a good sign. There could be a decrease but, for now, it’s good to know that at least it isn’t going higher.
The table shown by Patricia shows a lot of information, but what’s important are the health problems for the mother, the child, and the psychological effects on the family as well as financial problems in the family and society.
Some maternal problems are:
About the health of the child, there are a lot of health problems that can happen in babies in a twin pregnancy. Some of them are more common than others, for instance:
There are a lot of problems that can happen when having multiple pregnancies and another one of them is related to some societal issues, such as:
It’s very challenging, it’s very demanding to deal with one baby born, imagine with two, and even if there are some health conditions, that’s even more stressful for the couple or the mother.
It can be seen that there are a lot of problems and impacts that are very directly related to having multiple pregnancies. However, there are some stories of multiple pregnancies that ended up well and are very happy, but it’s important to remember that when the rates of multiple pregnancies are higher, all the risks mentioned are very present.
Despite all these aspects, couples insist on transferring more than one embryo because:
They’re suffering, they’re going through an IVF parkour for a long time, and they just want to have a baby as soon as possible, and we’re here to help them.
In the first chart shown, it’s demonstrated that the rates of pregnancy is more when transferring two than when transferring one. However, there isn’t much difference. As you can see, the rates of pregnancy when transferring one is 50% and the rates of having a pregnancy, twins or singletons, when transferring two is 57%.
It’s important to think if the difference in this percentage compensates for the risks, all the problems mentioned before, of having twins. If you’re told that the rates of having the pregnancy will go ahead, it’s pretty much the same.
Would you decide to have a dream pregnancy, knowing that you could have the risk of health problems for you and your baby? It depends if it was a twin pregnancy, so this is the question that’s important to take in mind.
Yes. There is a way of maximizing the odds of pregnancy and one of them is PGT.
This is the genetic preimplantation testing, a technique used when the embryo reaches the blastocyst stage. Then, the blastocyst is analyzed to see if there’s any genetic disease.
The chart shown is a study published by one of the worldwide leaders doing genetic testing called Igenomix and they have labs all around the world. In this chart it can be seen, in the blue bars, that when transferring one tested embryo, the rates of implantation are pretty much the same; thus, they’re all over 40%, no matter the age of the woman. However, if there’s a transfer of embryos without testing, through the age of the woman, the rates of implantation decrease considerably.
For this reason, genetic implantation is something highly recommended so when transferring embryos randomly without testing, the rates will drastically reduce as shown in the orange bars over the age of the woman.
It’s important to know that the PGT test doesn’t improve the quality of the embryo, but it shows that it’s a very high quality to be transferred. Patricia mentions there’s no medical test to improve the quality of an embryo, there are only medical tests to show the quality itself at the moment and to tell if there’s a genetic disease that probably won’t even pursue with the pregnancy because there are some genetic diseases not compatible with life, some of them are, but at this stage, they want to make sure that they’re transferring good quality embryos.
Therefore, PGT is a very important tool to use when legally possible because in some countries there are very restrictive conditions to use it and to go ahead with it. It’s also very important to prevent multiple pregnancies.
In the chart it can be seen that when transferring one single euploid blastocyst, meaning that it was tested, it’s normal, and there’s no genetic disease, the rates of live birth are 69%. Moreover, when transferring two embryos that weren’t tested, the rates of life birth were 72%.
As you can see, the difference of pregnancy and of life birth is not that big. The blue bars in this chart show that when transferring one single embryo the rates were zero because one tested embryo usually doesn’t give too much information. They already know that it’s not going to divide itself, so it’s going to be one single baby.
In the case of transferring two untested blastocysts, the rates of having twins goes to 48%. Therefore, when testing the embryos, they are sure that they’re going to have a single pregnancy, so no twins. This also shows that it’s going to be a healthy baby and, even though there are things they can never assure, it’s genetically normal. There’s only going to be a single baby.
This pre-implantation test is very, very useful and, when possible, we highly recommend it be done.
If PGT is not possible, due to multiple factors, Patricia states they can base a decision on transferring one or two embryos based on the female age. This also has a huge impact on the rates of the genetical and normal embryos.
The study of the American Society for Reproduction advises making this decision based on the quality of the embryos and the female age. This means that, for example, when having the tested embryos, the decision, no matter the age of the woman, is always to transfer one euploid embryo.
There are some changes as the woman gets older and older and when they have very good quality embryos, at least until 37 years old, the decision is always to transfer one euploid embryo as much as possible.
This study showed that the recommendation is more favourable to transferring one and maintaining the chance of success while reducing the risk of multiple pregnancies and all that comes with it. It’s known that for women having 41 or more years, the chance of having a healthy embryo is lower, so this is a very delicate decision to make. That’s why there are recommendations for transferring three or four embryos which also has an important decision based on the legislation of each country.
The numbers on the far right shown in the table are like that because over the age of 40 years old when they don’t have a PGT done, it’s important to consider that the rates of having genetically normal embryos are higher. So, that’s why there’s more advice to transfer more than two embryos. However, this decision must be made carefully, always with medical advice.
Another approach is to freeze the exceeded embryos. You’ve probably heard that frozen embryos and transferring them afterwards aren’t the same as transferring fresh embryos. This isn’t true. The study confirms that the rate of survival after cryopreservation is 99.5% by using the Kitazato products which are the top products and ways of freezing embryos in the world. These products are also used at Ferticentro.
If an embryo doesn’t survive after the frozen process, that loss is more highly related with the quality of the embryo and not to the technique to defrost it. When using these products, the quality and chance of implantation after the frosting process is equal and high as when transferring them fresh.
It’s important to know that 10 years ago, when using another technique called slow pulling, the rates of survival were about 60%, which is much lower that it is today using the technique of Kitazato. Moreover, in these situations, the recommendation would be to transfer 2 or more. This decision is justified because no one wants to lose embryos that were difficult and hard to get and then lose them under the freezing process.
However, nowadays, this is not accurate anymore. By using the appropriate vitrification techniques, with high rates of survival, transferring one is more than legit and even allows professionals to improve the quality of the endometrium in the uterus to receive the embryo.
According to Patricia, even at Ferticentro they sometimes use the freezing option because when doing the stimulation, some women don’t have the best conditions to transfer on that cycle due to the uterus not being good enough. So, they freeze all the embryos and transfer them on the next cycle, doing proper preparation.
Patients want a healthy baby and in the following study shown by Patricia, you can see the preference of patients when it comes to transfer one or two embryos and if they know the chances of getting pregnant. This would be pretty much the same when transferring one or two embryos.
Patricia states that this is not a real study but a theoretical question that was made to couples. This means that when having the knowledge of the rates of getting pregnant with the transfer of one or two embryos would be the same.
Even though more than 50% of the patients have all the information, they would still decide to transfer two because they want to have a baby as soon as possible. If patients knew that one of the rates of getting pregnant would be 1% less when transferring one, the decision would be even higher, almost 70%. Moreover, the 3% and 5% of less chances, the difference is even higher.
Once again, this is a theoretical situation, it didn’t happen. This is to explain that when doing the genetic testing, adapting the number of embryos to the female age, and using good techniques to freeze embryos, when explaining this to couples, they must be informed about the rates of having a baby when transferring only one is as good as transferring two. Thus, this is explained for them to make a decision with good knowledge and to avoid multiple pregnancies as much as possible.
Patricia mentions they have a clinic that has combined all these factors to inform about all the genetic tests that are able and reachable to the couples and adapt the clinical strategy to each case while maintaining the good chances of having a baby. All couples, single women or heterosexual couples, have the right to have all the knowledge before deciding because this is a very complex process, and the point is that everyone wants to have a healthy baby.
At Ferticentro, they would always recommend transferring only one embryo. There are certain situations when transferring two supplies and it has to be related to the quality of the embryos and the financial condition of the couple because they need to see that this is also an important question.
In Portugal, there’s a private section in health in IVF as well as at Ferticentro. This is a private clinic, and they always need to consider this because couples need to make a huge investment in this kind of treatment. Therefore, this is something they need to take in mind when advising in transferring one or two embryos.
Also, it’s important to take into account the health of the women, their family support, and the remaining embryos they had when deciding to transfer one or two.
The entire team at Ferticentro is involved in the decision, it’s not all about the doctors or the nurses, but of course the psychological department, the patient care department, and the laboratory, the embryologist that has the knowledge to tell us if transferring that good embryo, related with the quality, it’s the best option or not.
Nevertheless, the final decision is always made by the couple or the woman because they need to respect their decision, but they also consider all the information provided so they can make an informed decision.
At the end of the day, we all want the same, and that is having a baby at home, in our arms. A healthy baby, and we’re here to help you.
As I had shown in one of the charts, it depends on whether the embryo was tested or not because when transferring one tested embryo, no matter the age of the woman, the rate of live birth is pretty much the same. But, if the embryos aren’t tested, the rate of a woman transferring one embryo when having 42 is very different when 35 years old. So, that’s the difference if the embryo is tested, then the birth rates are pretty much the same, but if the embryo isn’t tested, that’s a very huge difference.
Yes, it was shown in one of the first charts. When transferring one embryo, there’s a very small percentage of having twins, but when transferring 2, it’s much higher. As you can see here, the amount of twins, it’s about 2%, so it shows that when transferring one embryo there’s a 2% chance of having twins. When transferring two embryos, there’s a chance of having even triplets, so there’s always a small chance that an embryo divides. In the 21st century, we have cases that happened in nature. We all know cases of women who had, during pregnancy, without doing any kind of IVF treatment, so this happens in nature, it can happen also in transferring only one single embryo. So, yes, that can happen.
There’s a small chance, but it can happen.
I didn’t say I never recommend transferring 2, even though it’s not me who recommends transferring two. We have at Ferticentro a policy that we all try as much as possible to transfer only one embryo. When there are cases, for example, a woman who didn’t get the chance to do the genetic testing and the embryos aren’t top quality, we need to see what the best options are.
In this kind of situation, we may advise transferring two, but this decision needs to be made with the knowledge of the doctor knowing the health conditions of the woman, and the knowledge of the biologists and embryologists to know if those embryos they recommend transferring because of the quality of them, and also the support and the family and the personal reasons from the couple or the female herself. We have situations where we can recommend two embryos, but most of the time, even when we’re talking about genetically tested embryos, we always recommend one embryo.
The PGT-A doesn’t damage the embryo, it’s with the very precise techniques that remove a very, very small part of the embryo that it’s enough to send to the lab and to get tested. So far, we didn’t have cases of damaging the embryos and those embryos, even if they were normal, then wouldn’t be able to be transferred because of the biopsy. That didn’t happen, even though not everyone at Ferticentro can do this biopsy. They need to have a certification; they need to do studies to be able to do these kinds of techniques.
The cost has to be discussed with the clinic or where you do the treatment because we also don’t do the tests, I mean the biopsy is done at Ferticentro, but then we send the biopsy to another lab (Igenomix), and they charge us. So, we need to charge a couple. The costs always depend on the number of embryos that are tested, so this is the question that has much to do with the country where you are doing and also the clinic.
There are several kinds of protocols we do. There’s always the medical point here, we need to see if there are any medical conditions associated that can interfere with the lining. Some women have some kind of problems related to fibroma, some cysts, and some other issues that sometimes make it more difficult to have a good lining. But, usually, the majority of the protocols that we do, are based on estrogens, and there are usually good results.
The advice, I don’t know if you’re talking about medication or some other aspect. What we recommend is that we need to have a good knowledge of the uterus before starting the preparation, and we need to know, that it’s very important if the cycles are regular because this can interfere. Sometimes we have cases when doing already the preparation with a woman who has very irregular cycles, that start doing the medical treatment. There are also things we can’t control, we can’t manage, and sometimes we need to start all over again, so this is very specific to each case.
No, we don’t. We just advise hysteroscopy after doing ultrasounds, when there are cases of some internal polyps that can interfere with the growth of the endometrium. If the woman has the usual regular cycles with no bleeding between cycles, between her periods, we don’t recommend hysteroscopy because it doesn’t raise the success of an IVF treatment. We always just recommend if there’s any case, any knowledge of internal polyp that is interfering with the endometrium growth. In this case, yes, we can recommend it, but it’s not regular.
That always depends on the quality of the embryos and also the type of treatment we’re doing. Usually, we do a D5 embryo, but that depends on the number of embryos that are available to transfer because imagine doing an IVF with your own eggs and, unfortunately, you only have three eggs available, for example, we will not go ahead with the D5 embryo because there may be no embryo available to transfer. If we have a good embryo to transfer on day three, we will do it on this day.
This decision of doing D3 or 5, always depends on the quality of the sperm and also the number of eggs available. This is a decision usually made on the day of the retrieval, after having information about how many eggs we have available to do the fecundation. If an embryo is good on day 3, the chances of having a pregnancy are as much as doing on D5.
The difference is that on day 5, we have more information about the embryo, and we have two embryos on D5, we have more information about them, and maybe we can see some differences between them, but on day 3, they probably look pretty much the same. So, the difference is that on day five, they give us more information about it, but if an embryo looks good and is in good condition and has developed perfectly on day three, it has as much chance of having implantation in the pregnancy as on day 5.
At Ferticentro we’ve been doing this more and more because this helps us to test the womb to the medication. Sometimes, it happens that we plan the endometrial preparation in a way, that doesn’t result, it doesn’t have a good outcome, and the endometrium does not grow, so when people and women have time and availability to do it, we advise doing a mock cycle.
It’s just mocking the same preparation as we would do for the embryo transfer and, if on the day of the ultrasound, before the embryo transfer, the endometrium is good, we confirm that that is the protocol to be used for the embryo transfer. That is our benefit, basically, sometimes we advise it more when women have more difficulty having the endometrium in good conditions, for example, a woman that has done chemotherapy, that are very difficult case has their endometrium growth because the endometrium doesn’t grow as they should, they don’t have periods anymore. For example, in people who don’t have ovaries anymore, the endometrium isn’t renewing. In some specific cases, we do a mock cycle because we have a lot of patients coming from abroad, so we don’t want them to prepare without knowing that it’s going to have a good outcome, so we just want them to come to Ferticentro after knowing that protocol is the right one.
Usually, in the majority of cases, we don’t do it because there are no health conditions that can tell us that the endometrium will be difficult to grow, but when we have already some background, some known history that in the specific case had IVF treatments over and over again, and the endometrium was not good enough, in that case, we always suggest a mock cycle.
No, I don’t think so. In Ferticentro we usually use 3 types of catheters. The decision on the type of catheter is just because of the uterus itself and the cervix. In some women, it can be very difficult to go through, and sometimes it’s needed a more flexible or less flexible catheter, so that’s why we make that decision on the type of catheter that we use, but that doesn’t have an influence on the pregnancy’s success.
