Oocytes, sperm and embryo genetic analysis after failed IVF cycle
For many patients, IVF is often considered the last resort on their way to parenthood. It’s what they turn to once all other options fail, and it’s often the method they put all of their hopes and faith in. What if it doesn’t work, however? As much as we don’t want to admit that, there is a possibility the first, second, or even the third IVF attempt will simply fail. What then?
Reproductive science is steadily marching progress, and modern genetic diagnostics allow us to observe, analyse and understand the process of fertility at every step of the way; following a failed IVF cycle, doctors and other specialists are able to pinpoint the precise reason for failure in most cases.
To explain modern analysis methods, we invited Dr Jon Aizpurua, founder and president of the IVF Spain group. His presentation will describe modern techniques and procedures which are employed to determine the genetic reasons behind IVF failures.
Parenthood has changed severely from what it used to be even a hundred years ago. In the 1960s, a social revolution took place, which made women postpone parenthood and instead focus on their education, careers and social life. The problem lies in the fact that biologically speaking, women are designed to become mothers in their twenties – the longer they wait, the less fertile they get. There exists a proven link between age and the increasing probability of aneuploidy in oocytes; aneuploid eggs result in aneuploid embryos, which often lead to miscarriages or don’t implant outright.
Due to this cultural shift, fertility rates are dropping in all of Europe. It’s simple enough to understand – it’s harder to achieve pregnancy at an older age, so women are having less children. This is true even in IVF scenarios – due to egg quality dropping with age, embryo transfers in own egg IVF have lower birth rates the older the patient is, dropping to below 10% by the age of 44.
Several solutions to this problem exist – younger patients, for instance, have access to egg banking. They can freeze their eggs now and use them whenever they’re ready. Egg donation is also available for older patients who didn’t freeze their eggs earlier. Success rates for embryo transfers do not drop with age, making it an attractive option for those past the age of 40.
The number of eggs – and their quality – for each woman drops with age. The precise reason for that has to do with genetics – the older an egg, the higher the probability of genetic errors appearing during its maturation process. If the eggs are fertilised, these errors are inherited by the embryo. These errors are the main reason for implantation failures, miscarriages, and congenital diseases such as Down syndrome in newborns. The precise term is “aneuploidy” – the condition of having an incorrect number of chromosomes.
What about sperm, however? Does it also have an age-dependent impact on the health of the embryo? Well, men are designed completely differently to women – their fertility does not go down with age as dramatically as it does for women. Despite this, the male factor accounts for around 40% of all infertility cases. This is mainly due to DNA defects in the sperm. These can be caused by urogenital infections, vascular diseases or lifestyle factors – smoking, excessive consumption of alcohol and a poor diet can all impact the quality of the sperm. As such, not only should basic sperm tests be mandatory – DNA fragmentation testing should also be performed.
At the end of the day, however, the male factor simply does not have as much of an impact on the success of IVF as the female factor does. Age, however, still plays a role in sperm quality. There is evidence suggesting that sperm from older men can cause pregnancy loss and genetic defects. However, because there are millions of cells available in each sample, diagnostic technology can be used to always pick out the healthiest ones to use. The same luxury, unfortunately, isn’t afforded to women and their oocytes. In the end, the female factor has more of an impact on the embryo’s health – and the older they are, the harder it is to produce several healthy embryos per stimulation cycle. There is about an 11% chance of a woman over the age of 42 producing a chromosomally normal embryo.
Thankfully, this is another area in which technology comes into play. Genetic screening allows us to select genetically healthy embryos for transfer, which drastically improves treatment success rates. PGT-A testing (previously known as PGS) is a widely used technique to determine embryo euploidy. Although it doesn’t actually “fix” embryos, it allows patients to save time (and money) by preventing them from wasting time by transferring defective embryos.
Egg quality isn’t the only factor to keep in mind – quantity also matters. Only certain eggs manage to generate strong embryos which reach the blastocyst stage in time. Only a certain portion of those blastocysts will be chromosomally normal. If there are twenty eggs, which result in five blastocysts, a certain portion of them being genetically normal – let’s say three of them. That’s three potential transfers – three potential children, in the best case scenario. The number of eggs produced through stimulation cycles drops with age, however – what if we only have five eggs to work with? What if we only manage to produce two blastocysts and neither of them is chromosomally normal? That’s when we resort to egg donation. This is why time is a major factor in the whole process of treating fertility.
Modern diagnostics and analysis methods allow doctors to evaluate the patient’s reproductive health based on certain parameters. These parameters can then be used to reliably calculate the amount of time and effort needed to produce a euploid blastocyst for the patient. Because of this possibility, the patient knows how many cycles will be needed to provide a reasonable chance of success, allowing them to decide whether they want to commit to treatment using their own eggs or not.
If they decide that the effort would be too much – or if the chances of success are too slim to even attempt treatment – egg donation remains as the last viable option. As we all know, success rates of egg donation programs are age-independent. Compared to conventional IVF treatments, egg donation seems like a very pragmatic solution: it’s efficient, safe, and well-regulated in most European countries. Genetic donor matching techniques are becoming increasingly popular – compared to traditional matching protocols, they allow for much more accuracy.
In conclusion, current technologies allow tailoring the treatment to the individual needs of the patient. The improvements in genetic diagnostics over the last 10-20 years have made reproductive medicine much more precise and efficient.
Questions and Answers from the event
I have low ovarian reserve (AMH 1.7), while my husband has severe male factor infertility. I’m 41, he’s 43. What treatment would you recommend? Is there any treatment to improve sperm count, DNA fragmentation, or egg quality?
An AMH of 1.7 at age 41 does not indicate low ovarian reserve. Like we said during the lecture, still having a relatively high AMH at that age means working with the patient’s own eggs is still a viable option – the question simply is, how many times the patient needs to be stimulated in order to produce at least one or two genetically normal blastocysts. The “treatment” we would recommend is simply embryo banking with PGS.
As for the male factor question, fragmentation and other issues related to the sperm are commonly a result of lifestyle choices. We ask the male partners to spend two months exercising, as well as taking high doses of antioxidants. If the quality of the sperm does not improve after those two months, there are other ways we can consider – such as direct extraction of sperm from the testes. Not to worry, the procedure is done under local anaesthesia.
Unfortunately, there is no cure yet for aging and lower reproductive potential; although that may potentially change within a decade or two.
I have a few questions. I had a failed transfer with IVF Spain last month. We used donor eggs and my husband’s sperm using TESA. I had a scratch in March before my real cycle, but still had a failed transfer. An ER-Map and a diagnostic hysteroscopy were recommended to me before the next transfer. We may not be able to come back for transfer until October or November, so would it be recommended to have a scratch again before the next transfer? I have also been told that I need a general anaesthetic for the hysteroscopy. Is it necessary? Also, I have heard that there is better success rates with a FET – why is this? My final question is that we have one 3BB and two 5BB blastocysts frozen and I wondered if it would be recommended to have the two 5BB blasts transferred on the next cycle to increase success – if not, why not? I was 46 years old in March.
Unfortunately, this patient did not get pregnant despite using egg donation – while it has the highest implantation rate in assisted reproduction, it’s not a magic bullet. It has an implantation rate of 70% – cumulatively, this number can go up to 95% after four transfers; this means, however, that for 30% of patients the first transfer will fail.
When a transfer like that fails, our doctors start investigating the reasons behind the failure – congenital defects within the uterus, immunological reasons, et cetera. There are a lot of treatments available for implantation failure – which means you shouldn’t give up after a failed transfer!
As this patient is one of ours, we’re going to answer this question in a more generalised fashion in order to preserve confidentiality. Regarding the scratch, if the patient wishes to perform a transfer in October, performing the scratch now makes absolutely no sense – the effects of a scratch last from one to (very rarely) three months. So, if she wants to perform the transfer in October, the scratch should be done in August or September.
As for the ER-Map, it’s also a technique using endometrial scratching, however, the benefits of it are immediate and are unrelated to the transfer. ER-Map, or the Endometrial Receptivity Map, tells us about the correct implantation window of the patient. Because the results don’t change over time, this can be done now, or at the same time as the endometrial scratch before the transfer cycle.
In general, however, as long as the patient can generate good embryos and we can investigate the endometrium deeper, her chances are still very good. Keep calm and carry on!
What do you do with mosaic embryos?
Previously, it was thought that mosaic embryos were defective – they start with one cell, divide into two, four, eight, sixteen, et cetera – and suddenly, we find a cell that’s defective. That’s how mosaicism is detected. The question then becomes “was the original cell defective”? Was the embryo always defective, or is this something that happened during its development?
Whatever the answer, the major fear was that those imperfect cells can negatively impact development – resulting in an aneuploid embryo. As science on the subject progressed, however, we learned that in fact, the opposite happens. If the embryo contains many healthy cells and just one that is not perfect, there is a capability within each cell to correct itself.
We used not to transfer mosaic embryos for safety reasons. In the last couple years, thanks to ongoing research on the topic, we have learned that many of those embryos – as long as the mosaicism does not affect the chromosomes commonly associated with aneuploidy – have a capability of restructuring themselves. Obviously, their implantation rates are lower, but they still result in healthy children being born. As such, if the worst option is the embryo not implanting, we can recommend going forward with transferring a mosaic embryo. We also recommend mosaic embryo transfer to patients who don’t have a lot of viable embryos to begin with.
What would be the cause of implantation failure with euploid embryos?
Implantation is affected by two main factors: the embryo itself and the environment into which it’s transferred. The process of implantation is very complex and it mostly has to do with the embryo. As the embryo implants, the first thing it does is express over 500 factors in its first “message” to the uterus – “I am here, I am healthy, I am fit” et cetera. In response, the endometrium responds in the order of factors the embryo expresses in a sort of dialogue.
However, the endometrium itself is a very important piece of the puzzle and it is the reason why euploid embryos sometimes do not implant; the endometrium’s response may not be satisfactory. For instance, if the endometrium is in the wrong phase of the cycle – outside of its receptivity window – the embryo may not implant. This is one of the more common causes of implantation failure. Immunological problems are also one of the classic causes, along with vascular issues and anatomical defects.
If a transfer fails despite using donor eggs and euploid blastocysts, we have to take into account all of these other issues – infections, immunological disorders, blood supply issues et cetera.
What is the success rate for the first cycle using donor eggs?
Because of how egg donation is conducted, we can reliably count on the embryos being of high quality; currently, implantation rates during the first cycle average to around 70%. For some patients – and some doctors, for that matter, this is not enough. Thus, at IVF Spain, we offer additional programs aimed at beating the odds. In one of these programs, we generate as many embryos from the same donor as possible and freeze them; in case the first transfer fails, we perform detailed testing in order to determine the cause of failure before the second transfer. Because of that, your cumulative pregnancy rate after two transfers is 80%.
If, for some reason, that doesn’t work and we’re sure we’re working with great quality embryos, good quality donor, the endometrium has been double checked, et cetera, we perform a third transfer, this time with immunological protocols depending on the patient’s prognosis. In over 90% of cases treated at IVF Spain using the exclusive egg donation program, the patients have children.
For some patients, even that 90% is not good enough. That’s when we pull out the big guns – metaphorically speaking. Exclusive class egg donation gives the patient a guarantee of five high quality blastocysts from the same donor. If we see that three transfers from the same donor have failed, the clinic is obligated to generate two more blastocysts at no extra cost from a second donor – this time, matched not only using the regular matching methods, but also by immunological factors. In 90% of cases this results in a healthy live birth. That’s the best we can do at this time.
I am 38 years old and I have extremely low AMH (0.3-0.4). I have done 2 IVF cycles, each one resulting in just one aneuploid blastocyst. Would you recommend I try another IVF cycle with my own eggs or should I go straight for donor eggs?
One of the most challenging cases we ever treated at IVF Spain was a 27 year old patient with this kind of AMH. We did three or four cycles of embryo banking. We were eventually able to transfer chromosomally normal embryos. What’s more, the patient came back two years later to try for a second child. At that point, she was already menopausal; however, we have been able to grow her endometrial lining with artificial hormones and transfer her frozen embryos from years back.
Before we commit to a decision with any patient, we examine three factors: their age, AMH and antral follicle count. If you are strong and want to fight for your genetics, then strategies such as embryo banking can be employed to help you overcome infertility.
I did the ERA test. During the test cycle, I only took oestrogen and progesterone. Is it important to take the same dosages of hormones in the transfer cycle? I was recommended to take heparin, ASS and prednisolone in addition to oestrogen and progesterone. Can these medications have an impact on the window of implantation? Are the results of the ERA test still meaningful if I take additional medication?
To answer the first question, yes, of course. If you want to apply the findings of a predictive test, such as the ERA test, all the conditions must be the same. The progesterone is the really crucial part, as it is responsible for transforming the endometrium into a receptive state.
As for the additional medication, there is evidence to support their use in certain circumstances. Heparin, for example, helps with clotting issues. In that case, it’s not optional, as it helps mitigate serious issues which could arise during the pregnancy. Medications such as these don’t have an impact on the window of implantation.
The ERA test results are not affected by the medication.
Time-lapse can be expensive – can it help determine the best quality blastocysts to transfer?
There are different ways of selecting the embryos to transfer upfront. Time-lapse technology shows us which embryos have reached certain stages of their development at a certain time; because of this, we are able to predict which embryos are highly likely to result in successful pregnancies.
We classify embryos into three categories – A, B, and C. A-quality embryos are the ones which develop the fastest and meet certain criteria which means they have a high chance of developing into a successful pregnancy. B-quality embryos are a little bit slower, but still meet the criteria. C-quality embryos are very slow. Success rates when using A and B-quality embryos are very comparable to each other.
Different time-lapse systems have different criteria deciding which embryos are high quality and which aren’t; the difference between them may not be as clear cut as you may assume, however. C-quality embryos have been known to result in successful pregnancies in the past. They enjoy an implantation rate of around 20% – relatively low, but they still have a fighting chance. Compare that with B and A-quality embryos: 50% and 60-70%, respectively.
Time-lapse systems can be also used to predict whether or not embryos are euploid or not. Coming back to your question – time-lapse or embryoscope monitoring isn’t that expensive, especially when compared with other methods of gauging embryo quality. As you can see, however, yes – it does help us select the best quality embryos.
Is egg donation anonymous in all parts of Spain? Is there a possibility that egg donation becomes open any time soon?
There is a big misunderstanding regarding “open donations”. The anonymity enforced by Spanish law affects only the parents in the egg donation scenario in order to avoid a biased selection of donors by reasons that have nothing to do with actual medicine. That is the case in the United States, for instance, where parents can choose donors based on their IQ, education, et cetera – when in reality, these factors have no bearing on how the child develops. In our opinion, that is a very bad way of commercializing medicine, as it presents IVF as a chance to have “a perfect child” – while in reality, the goal of IVF is to help patients achieve their dream of having a child at all.
To that end, the anonymity compromise currently in place in Spain and in other countries around the world ensures that the patient is matched with a donor most similar to them; not only in appearance, but also genetics and educational background. The child, once it reaches the age of 18, can track back the donor, if it so chooses. The only reason for anonymity is to prevent parents from biasing the donor matching process with irrelevant preferences.
Having said that, I don’t think we require a change in the law – it works well, as evidenced by the fact that we have many donors, while countries with other laws don’t. Sometimes, egg donation is also compared to adoptions, which are completely different scenarios, as adoptions carry additional psychological implications not present in egg donation scenarios.
Research has shown successful sperm recovery in Klinefelter’s syndrome, but a slightly increased risk of aneuploidies. What is your experience regarding Klinefelter’s?
There have been different approaches of selecting sperm cells with the right amount of chromosomes. However, because manipulating and testing sperm, such as with a cytometer, has been shown to damage the sample and lower the success rate of the entire cycle, we now test embryos themselves. It gives us a clear picture of how many embryos are affected by chromosomal imbalances. PGS technology allows us to detect trisomies and other anomalies.
How long does embryo banking take?
Embryo banking depends on your ovarian reserves. If your AMH is under 2, we have to do at least two cycles; the goal is six to eight blastocysts. Following the first cycle, we have you recover for two or three months before doing another cycle. We usually prescribe patients two months of rest before another stimulation cycle, so two embryo banking cycles take around two or three months, four cycles take around eight months et cetera.
Does stimulation level affect egg quality? Is PICSI or MACS useful in selecting the sperm for ICSI? Can sperm diagnostics reveal the cause of implantation failure? What is the chance to perform an ICSI treatment with my results – OAT III, DFI 17-24%, normal chromosome distribution – in comparison with normal sperm? What happens if you select a sperm with DNA fragmentation for ICSI? Is PGS/PGT useful? My wife is 33 years old, AMH 1.4, 14 failed ICSI with three abortions; I’m 38 years old, OAT III, DFI 17-24%, no abnormalities revealed by the FISH test – what’s your recommendation? Egg donation or additional treatments with own eggs?
Obviously you can overstimulate eggs; this is why doses are appropriately adjusted for each patient. Too many hormones – the egg quality goes down. Too little, however, and you get very few eggs. A proper balance is needed in order to achieve optimal results.
In my personal opinion both MACS is useful, but there’s a lot of controversy around PICSI. There’s more evidence to show that MACS is useful in fighting apoptosis.
As I mentioned in the lecture, there are poor sperm profiles which could affect the epigenetic capabilities of the embryo. Fragmentation can also affect the activation of certain genes – like I mentioned, the embryo has about 500 genes that need to interact correctly with the endometrium. If the male part of those genes is fragmented, they may not activate correctly, resulting in an Implantation failure.
As for your results, they have no bearing on ICSI, as it only requires a single sperm cell. The issue is fragmentation, and how to decrease it. There are different approaches, as I explained previously – medication, antioxidants, lifestyle adjustments, and others. Of particular note is the HAF protocol, which stands for High Activation Frequency. If the man ejaculates every second day for ten days before the fertilisation, most of the fragmentation simply disappears. We also mentioned that if all else fails, we can take sperm cells directly from the testes.
A large meta-analysis study has shown that fragmentation does not influence the fertilization index very much; there are other factors that influence fertilization more. The impact of fragmentation on fertilization is low; however, like I just mentioned, the impact of fragmentation on the activation of certain genes during implantation is high. As such, while fertilization rates remain high, implantation rates go down when using fragmented sperm.
PGS and PGT are diagnostic tools, allowing us to determine which embryos have a better chance of implantation, and which have no chance of successfully implanting – from a given amount of embryos. This is widely misunderstood – using PGT does not make embryos better or worse. All the testing does is save time – by not transferring embryos which have no chance at all, the patient can undergo less treatments. If you take this into account the costs of multiple transfers in case of failure, the storage of frozen embryos et cetera, you actually save money by investing in testing, as it can directly pinpoint which embryo to transfer and which should be left alone.
We wouldn’t recommend egg donation when the female patient is 33 years old and has an AMH of 1.4. She would benefit greatly from using sperm directly from the testes, as well as advanced stimulation protocols and genetic testing of the embryos.
Is it necessary to have a general anaesthetic for a hysteroscopy? Can it be done under local anaesthesia?
It depends on the pain tolerance and anxiety the patient experiences. We have some patients that don’t need anything at all, for instance. Some only experience major anxiety – we use sedation in that case. General anaesthesia is generally not needed.
Should I do the ERA test if I attempted implantation twice?
The ERA test is the correct approach. If a patient transferred two high quality embryos and they did not implant, the first step we do is verify the correct implantation window by performing the ERA test. Additionally, diagnosing the endometrial lining is also recommended, which can be tested using endometrial receptivity mapping. If those tests don’t help, immunological testing should be the next place you look at.
My husband has low sperm count. We tried IVF but had three failed cycles: two chemical pregnancies and one miscarriage. Would PGS be recommended? What’s the difference between PGS and PGD?
PGS stands for Pre-Implantation Genetic Screening, while PGD stands for Pre-Implantation Genetic Diagnosis. Screening is performed on a number of chromosomes in order to rule out the possibility of Down’s syndrome, Edwards Syndrome, and others.
PGD is performed when patients are carriers of or suffer from genetic diseases such as cystic fibrosis.
Going back to your question, we would need to test your husband’s sperm count and hormonal levels. If they allow for further treatment, we can prescribe medication to improve the sperm count. If you’re above 35 years old, PGS is definitely recommended.
How do IVF Spain test for Immunological problems? Or do they prescribe medication without testing for immunological issues?
In IVF Spain we don’t prescribe any medication without indications – we can’t treat someone if we don’t know what exactly we’re treating. The most common immunological test we perform is the endometrial lining biopsy. On day 21 of the test cycle, when we test the receptivity, we also test the immune system by calculating the number of NK cells, TH1, TH2 cell ratio, et cetera; depending on those results, we treat in accordance with the indications.
Do you time the medication to give patients the best chance of implantation?
Most centres perform transfers in substitute artificial cycles, which means the use of artificial hormones. After 15 days of oestrogen, we scan the endometrium to see how thick the lining is – usually we want to see a lining of seven to twelve millimetres. If this measurement is achieved, we know the hormone dose is well adjusted and we continue with it. Otherwise, we adjust. We also add five days of progesterone before the transfer in order to open the implantation window. For around 70% of our patients, five to five and a half days of progesterone is sufficient – the other 30% need more time.
What can be done to “improve the answer of the endometrium” during implantation?
The first thing that needs to be addressed is the thickness of the lining, as it is the most common issue –patients who experienced miscarriages or other issues often have problem growing the endometrium to a satisfactory thickness.
Fir cases where we have tried everything – highest doses of hormones, biopsies, et cetera – without success, IVF Spain have developed a special program in which a hysteroscopy is performed at the beginning of a cycle with the addition of micro-needling. The micro-needling activates the stromal cells at the bottom of the endometrial lining, which improves growth.
We have been using autologous stem cells to stimulate aging ovaries and premature ovarian failure. The results aren’t encouraging. How are your results in Spain? Or stem cell lab is in India, as we have a lot of researchers there.
We don’t perform those treatments in Spain, and to our knowledge no research like that has been published around the world. Basic research on the topic is performed, but clinical use is still years away.
I had a failed IVF this month; a second day transfer resulted in implantation failure. What could have caused the failure?
Implantation is the matter of rheology, immunology, enzymatic and hormonal activities, and others. Only an assessment of all of these factors in an appropriate way can answer that question. A lot of factors are involved and we can’t give an accurate answer based on such limited information.
Some error has occured.