In this webinar, Dr Harry Karpouzis, MD, Founder & Scientific Director at IVF Pelargos Fertility Group, Athens, Greece has discussed endometrial factors that cause recurrent failed IVF attempts. Dr Karpouzis has also, provided how to diagnose it and what are the treatment options.
The success of an IVF depends on the embryo, which is a very important factor. It includes the quality and the chromosomes of the embryo, but it also depends on the endometrium, the lining of the womb and medical factors like a thyroid gland, immunological factors, and endometriosis. The endometrium is not considered like the eggs, the embryo, or the sperm, but it is equally significant. Many proteins and molecules play a role in the implantation of the embryo, but their coordinated contribution is very poorly understood. Nowadays, molecular biochemistry and genetics help us a lot to understand it.
The most common endometrial factors that can cause recurrent implantation failure and the easiest to understand are the anatomic factors. These are polyps inside the endometrium, a fibroid protruding inside the endometrium, a septum, a congenital septum or adhesions called Ashermans. All those factors play a very important role in the implantation of an embryo. We can diagnose those with the 3d ultrasound, which is a non-invasive procedure, and hysteroscopy, which is an invasive procedure, it’s diagnostic but at the same time can be used to treat patients.
Polyps
Polyps are very common, and 10% of the general female population has them. Some research shows that they are more frequent in women with endometriosis, and they can affect fertility, both spontaneous and IVF implantation of the embryo with different factors:
- can cause a mechanical interference with the sperm transport
- can be related to inflammation
- can cause mechanical interference with the implantation
- can also alter the production of many endometrial receptive factors
How can polyps be diagnosed?
- ultrasound, 3D ultrasound, HSG, HyCoSy, Aquascan or Hydrosono, hysteroscopy
- they can be removed to improve the implantation rates in IVF and spontaneous conception
- if identified at the time of IVF, then it’s better to freeze the embryos
Fibroids
Fibroids are also very common, they occur in around 3-10% of women of reproductive age. In African origin women, the percentage is even higher. We can diagnose them with 3D ultrasounds or MRI if there are a lot of fibroids, and it’s difficult to get a clear picture of where exactly each of the fibroids is located. The data and the research shows that fibroids that are close to the cavity interfere with the cavity or distort the cavity, and it can be associated with recurrent miscarriages. Some research shows that 8.2% of women with recurrent miscarriages have a fibroid, which is close to the cavity and affects the cavity. Some fibroids protrude inside the cavity, and those are the submucosal fibroids. Some fibroids are inside the womb muscle, and they are the neural ones, and there are also the subserosal ones in the serosa. There is clear evidence that the submucosal fibroids need to be removed before IVF because they can impact fertility, they can affect implantation rates, and they can significantly reduce the outcomes.
It is a bit more difficult to decide what to do with intramural and subserosal fibroids, generally, intramural fibroids which are less than 4 or 5 centimetres in size and are not protruding from the cavity inside, are better to remove at least in the first attempt of IVF. There are quite significant data that says they might not play an important role. If the fibroids are more than 5-6 centimetres, it needs to be removed unless there is a very specific reason for not doing that, for example, in a medical region that affects a woman’s health.
Fibroids with more than 50% projection in the cavity need to be removed. On the other hand, removing fibroids with less than 50% projection in the cavity is more complex, and many factors need to be considered, such as hysteroscopic assessment, woman’s age, if there were any previous implantation failures or surgeries, AMH levels,
According to Dr Karpouzis, when we are dealing with submucosal fibroids, they need to be removed by hysteroscopy and if they are more than 3 centimetres, it’s better to use GnRH analogues before to reduce their size a bit and then remove them. GnRH help to avoid the risk of the second stage is reduced. Before giving GnRH analogues, it is necessary to consider other factors like AMH, age, etc. If there is a low AMH and advanced maternal age, and we are dealing with a poor responder, it would be better to retrieve the eggs first. Then go ahead with the removal of the fibroids because GnRH can down-regulate the ovaries and make them more difficult to stimulate them again after that.
Intramuscular or big subserosal fibroids need to be removed with laparoscopy. If they are more than 50% submucosal, then hysteroscopy can be done, but it needs to be done correctly without compromising the cavity, technically, it is a difficult operation. If less than 50% is protruding inside the cavity, then possibly the best thing would be to remove it with laparoscopy and combine it with a hysteroscopy.
Septum intrauterine
The septum is usually congenital, it can mechanically affect the implantation, can reduce the size of the cavity, affect the sperm transporter, can be a consequence of inflammation as well, and can increase the miscarriage rate. Various research shows septums can increase the miscarriage rate between 20-40%. They can also cause preterm deliveries, increase the rate of caesarean section, and breach the position of the baby. It is sometimes difficult to find out if it is a septate or bicornuate uterus, and the management is completely different for each. Therefore, using 3D ultrasound, MRI, HSG, Hydrosono, HyCoSy, and hysteroscopy, is the gold standard to check what is happening.
The septum can be removed with the use of a Hysteroscopic Metroplasty resectoscope, whether with scissors or a laser. When the embryo transfer is delayed, it would be preferable to take antibiotics and do some hormonal treatment with estrogen to keep the septum from coming back. Sometimes also intrauterine device (IUD) can be used, we can use estrogen priming a go ahead with IVF after the removal of the septum.
Adhesions
Adhesions or Ashermans’ syndrome, most of the time, occur post-surgery, or after infections. It’s suspected by ultrasound when the lining of the womb is not a good size or it doesn’t look healthy, it’s not trilaminar. Also, colour Dopplers can help in finding out, but the gold standard is hysteroscopy. Adhesions can cause infertility, recurrent pregnancy loss, and preterm deliveries, it is very difficult to deal with them, and when we see them, we try to separate the adhesions. We do that with hysteroscopic adhesiolysis, antibiotics, estrogen treatment, and IUD, several studies say that the use of vitamin E can be helpful, with Sildenafil (Viagra), there is no clear evidence behind that. The last thing we can do with the endometrium if even after hysteroscopic adhesiolysis is not increasing in size is using a growth factor called Granulocyte colony-stimulating factor (G-CSF), which can sometimes help in increasing the thickness, but nothing can guarantee that endometrium will be healthy. The last resort is surrogacy.
Thin endometrium
One of the most common reasons for a thin endometrium is Asherman’s syndrome, it can also be an infection, either an acute one or a chronic infection. It can also be associated with tuberculosis sometimes and in many cases, it is related to medication like Clomid, for example, we know that it can reduce the thickness of the womb, if it does, we need to change medication. There are cases with no history of D&Cs or myomectomies, infections and et the endometrium is not getting thicker than 7 millimetres, it is quite common in IVF. Most of the time, thin endometrium can also be associated with poor glandular epithelium, high uterine blood flow impedance, decreased growth factors and cytokines.
Some data says that the cut-off limit is 7 millimetres and there is a significant drop in the probability of pregnancy below 2.4%. Another research showed that the ideal thickness is between 9 and 14 millimetres, and when they are compared to that 7-8 millimetres, the pregnancy rates are higher. However, pregnancies have been reported with thinner endometrial thickness of less than that. It’s not only the thickness, other factors need to be taken into consideration as well, for example, if it is trilaminar endometrium, if it is hyperechoic and if there is any blood flow inside the endometrium. We can check that with Colour Dopplers, with 3D ultrasound, we can set the endometrial volume. There is a lot of research that shows that all these factors can play a role.
The first thing that can be done if we are dealing with a thin endometrium is to find out if there is an anatomical reason, like Asherman’s syndrome, or adhesions, we use hysteroscopy for that. If there are adhesions, we can divide them.
Chronic endometritis
When we do the hysteroscopy, many times it can also be associated with chronic endometritis. Vaginal cervical cultures are not very accurate when we are looking for an infection inside, we can take endometrial cultures, and we can do it either as an outpatient procedure or at the time of hysteroscopies like ERA test or ALICE test. There are specific signs during hysteroscopy that can show chronic endometritis, such as hyperaemia or oedema (thickness of the endometrium) and micropolyps. All those factors have a high sensitivity, specificity and positive and negative predictive values of the hysteroscopy of about 92.7%, and if we also see micropolyps inside, it further increases it, 63.7% of the cases that we have made the diagnosis with hysteroscopy are confirmed with histology.
The most common bacteria are streptococcus, E-coli, enterococcus, ureaplasma, and chlamydia only 2.7%. There are several treatment options to deal with bacteria. Treatment with Doxycycline for 14 days, if it’s a culture that confirms that we are talking about the gram-negative bacteria, then we give Ciprofloxacin for 10 days, if it is a gram-positive, it’s Amoxicillin plus Clavulanic for 8 days. It’s possible to use a combination of those. In the case of a negative bacterial sample but positive histological and hysteroscopic diagnosis, we use Ceftriaxone, Doxycycline and Metronidazole for 14 days. Therefore, antibiotics can help a lot if we have a diagnosis of chronic endometritis.
Herpes
Herpes can affect the endometrium, and some data says that the presence of HHV-6A DNA (herpes DNA in endometrial cells) can alter the hormonal environment. There is data that shows that estradiol levels are higher, which are most probably favourable for herpes. With that specific herpes, the immune environment is altered. Some uterine natural killer cells (NK) are lower, but they get higher activation. The Interleukin 10 (IL-10) is elevated, and the TH1/ TH2 ratio is increased. We know that this ratio is associated with infertility in reproductive immunology.
Other reasons
We know that some medication can affect the thickness of the endometrium when we do a frozen embryo transfer, but we don’t down-regulate, most of the time, it doesn’t play any role, but some people react differently. Estrogen (Progynova) protocols can also affect the pituitary by down-regulating, and again, this can negatively affect the endometrium. When we start with estrogen, we know that sometimes ovulation can happen, and this can cause problems in the implantation. Clomid can also affect the thickness, so sometimes, we need to change the medication. Sometimes, it is better to give dermal patches instead of oral medication because sometimes people react better to them.
If we don’t have any obvious reason for thin endometrium and we do a hysteroscopy, and the result is normal, it’s best to do a natural cycle tracking. It means that we observe how the endometrium is increasing in the natural cycle, and we see sometimes that the endometrium may increase when the follicle grows more than 18-24 millimetres in size.
Granulocyte colony-stimulating factor (G-CSF)
G-CSF, growth factor increases the mesenchymal and haematopoietic stem cells which means that it causes a regeneration of the endometrium. In 2011, a lot of data was collected that shows improvement when everything else has failed. We use it in cases of very persistent endometrium that is not getting thicker before we decide to go to surrogacy.
Endometrium & hormones
The endometrium is related to hormones, and sometimes estrogen and progesterone are enough for implantation. We need to have good estrogen priming before we start the progesterone and there is data that shows that the ideal is 12 to 18 days of estrogen, less than 9 days is not enough. Then we give progesterone which prepares the endometrium for implantation and the implantation happens about 7 days after the trigger after the ovulation, and the implantation window can vary about 2 days. Progesterone levels are very important as well before the embryo transfer. When we are talking about the frozen cycle, then progesterone levels ideally should be more than 12.
ERA test
It was discovered in 2011, it shows the implantation window before it happens, about 8-10 days post ovulation. Molecular biology has identified a unique genomic signature of endometrial receptivity, and it diagnoses the molecular status of the receptive endometrium according to its transcriptional signatures regardless of its histological appearance. It analyzes 238 genes, and we can find out if the endometrium is receptive after 5 days of progesterone, before or more than that, it can be pre-receptive or post-receptive. ERA test is combined with the ALICE test, which shows if there is chronic endometritis. The EMMA test shows if there are good bacteria in the endometrial microbiome. These tests are very important in cases of unexplained failures without any other obvious reasons and good embryos.
Endometriosis
It can affect the endometrium too, it causes a hostile environment that can affect implantation, and it doesn’t only affect the quality of the eggs. Usually, when we suspect endometriosis, it is either good to down-regulate the ovaries and suppress the disease before the transfer or even operate in cases of severe degree. Is it better to operate before or after the egg retrieval? That depends on many factors, before an embryo transfer, if we have frozen embryos, we need to down-regulate and suppress the disease, we need to create a healthy environment before we do the transfer. To identify the endometriosis, we can do laparoscopy, or sometimes there are some new tests like the ERA test, where a specific protein BCLX6 is identified. If the result is positive, women are 5 times less likely to succeed in IVF. That way we can identify endometriosis without the need for a laparoscopy.
Conclusions
Even if the embryo is thoroughly investigated, we need to remember that it’s not the only factor. The endometrium can play a very important role as well in the whole process of implantation window, bad hormones, receptors, cytokines, genes, proteins, all those things play a role as it’s the coordination of them that makes the implantation happen, it’s not completely understood. Molecular biology and genetics help a lot to understand that with the new tests, but there is a long way to go. The most important thing is to have a personalized approach and keep in mind unexplained infertility is less and less unexplained.
