Endometrial investigations
The uterine lining plays a crucial role in implantation and the early development of a pregnancy. In selected situations, further investigations of the endometrium may therefore be useful in cases of repeated implantation failure or recurrent miscarriages.
The focus is in particular on testing for chronic endometritis, an inflammation of the uterine lining that often causes few symptoms and can be diagnosed by detecting CD138-positive plasma cells in an endometrial biopsy.
In addition, depending on your individual medical history, other endometrial investigations may be considered, such as an analysis of the endometrial microbiome. The scientific evidence for these procedures varies: in particular, the significance of the uterine microbiome, optimal cut-off values, and the benefit of therapies derived from it are still being investigated scientifically.
When are endometrial investigations useful in cases of an as-yet unfulfilled wish to have a child?
Further investigations of the uterine lining are not part of routine basic fertility diagnostics. They may be considered in particular if pregnancies repeatedly do not occur or if there are recurrent miscarriages. Which test is appropriate depends on the individual medical history.
Repeated implantation failure
If pregnancy does not occur despite repeated transfers of good-quality embryos, further investigation of the endometrium may be useful. In particular, chronic endometritis can be assessed by detecting CD138-positive plasma cells. In selected cases, a microbiome analysis or special investigations such as uterine killer cells may also be discussed. However, the clinical benefit of these additional tests has not yet been clearly established.
Recurrent miscarriages
In cases of recurrent miscarriages, chronic endometritis can be investigated as a possible additional factor. For this purpose, a small sample of the uterine lining is taken and examined for CD138-positive plasma cells. Microbiome and immunological investigations may be discussed as an adjunct in special constellations, but they are not part of routinely recommended miscarriage diagnostics.
Suspected chronic endometritis
Chronic endometritis often causes no symptoms or only non-specific symptoms and may therefore go unnoticed. If the medical history suggests it, an endometrial biopsy with testing for CD138-positive plasma cells can provide indications of chronic inflammation. Depending on the findings and the clinical question, an additional microbiological or molecular biological test for specific pathogens or the endometrial microbiome may be useful.
What endometrial investigations are available?
We therefore do not recommend extended endometrial diagnostics routinely, but rather selectively based on your individual medical history and previous fertility treatment.
Chronic endometritis is an inflammation of the uterine lining that usually causes few symptoms or goes completely unnoticed. It is associated with recurrent miscarriages and possibly also with repeated implantation failure.
For diagnosis, we take a small sample of the uterine lining. This is examined histologically and, in particular, checked for CD138-positive plasma cells. Evidence of increased plasma cells may indicate chronic endometritis.
However, there is currently no internationally uniform cut-off value for the number of plasma cells above which clinically relevant chronic endometritis is present. We therefore always assess the findings in the context of your individual medical history and previous fertility treatments.
If clinically relevant chronic endometritis is diagnosed, antibiotic treatment may be considered. Studies show more favorable reproductive outcomes, particularly when chronic endometritis is no longer detectable after treatment; at the same time, the evidence on improving the live birth rate has not yet been conclusively clarified.
Make an appointmentThe endometrium is the lining that covers the inside of the uterus. It is colonized by bacteria, primarily protective lactobacilli (lactic acid bacteria). Modern molecular biological methods can detect bacterial DNA and different bacterial profiles in the endometrium. Among other things, this examines whether lactobacilli dominate or whether there are indications of so-called dysbiosis—an altered bacterial composition.
Studies show associations between certain microbial patterns and the chances of pregnancy. However, it has not yet been conclusively clarified how an “optimal” endometrial microbiome should be defined, which cut-off values are clinically relevant, and whether targeted modification of the microbiome improves pregnancy or live birth rates. The microbiome analysis is therefore not a routine test. In selected patients—especially after repeated implantation failure and in conjunction with further indications of chronic endometritis—it can be used as an additional diagnostic tool.
Make an appointmentUterine natural killer cells are a natural component of the immune system of the uterine lining and play an important role in implantation, placental development, and immunological communication between mother and embryo.
In cases of repeated implantation failure or miscarriages, the number and function of these cells are being intensively studied scientifically. However, there are still no uniform reference ranges and sufficiently validated methods to reliably derive a cause or therapy from an increased or decreased uNK value.
Determining uterine NK cells is therefore not part of routinely recommended fertility diagnostics. In special situations, particularly after repeated implantation failure, it may be performed as an additional test following individual counseling.
Make an appointmentWhat role does the microbiome play when trying to conceive?
The uterine lining plays a central role in the implantation of an embryo. In recent years, intensive research has therefore examined whether chronic inflammation and changes in the endometrial microbiome can contribute to repeated implantation failure or miscarriages.
Chronic endometritis is particularly relevant. This persistent inflammation of the uterine lining often causes no symptoms and therefore usually remains undetected without targeted testing. It can be detected by an endometrial biopsy and testing for CD138-positive plasma cells. The clinical evidence for this diagnostic approach is stronger than for many other specialized endometrial investigations.
Studies also show associations between changes in the endometrial microbiome and implantation and the course of pregnancy. Among other things, reduced dominance of lactobacilli and an increased presence of certain other bacteria are being investigated. However, it has not yet been conclusively clarified which composition of the endometrial microbiome should be considered optimal and whether targeted treatment of dysbiosis improves pregnancy or live birth rates.
In our view, extended endometrial diagnostics should therefore not be performed routinely for every patient trying to conceive. However, in cases of repeated implantation failure, recurrent miscarriages, or selected complex fertility histories, it can provide additional information. Which test is appropriate in an individual case is decided based on your medical history, previous treatments, and existing findings—also taking into account the varying scientific evidence for the individual procedures.
Additional diagnostics when trying to conceive
Hormonal factors can influence the cycle, ovulation, and the build-up of the uterine lining. Depending on the clinical question, we may examine, for example, thyroid values, prolactin, estradiol and progesterone, as well as other hormones, in order to identify possible hormonal causes.
A hysteroscopy allows the uterine cavity to be assessed directly. For example, polyps, submucosal fibroids, adhesions, or other changes that may impair implantation can be detected. If needed, targeted tissue samples can also be taken during the procedure.
In cases of repeated implantation failure or recurrent miscarriages, we do not only look at the uterine lining. Depending on your medical history, further investigations may be useful—for example, of uterine anatomy, genetics, coagulation, immunology, or male factors.
Procedure for endometrial diagnostics
At our private fertility center in Munich, we guide you step by step through diagnostics and possible treatment options. Which test is appropriate and when the tissue sample is taken depends on the specific clinical question. Some tests can be performed flexibly within the cycle, while others require a precisely defined time point.
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Individual planning
First, we discuss which endometrial investigation is appropriate in your situation. The timing of the biopsy is planned accordingly: tests for chronic endometritis or CD138-positive plasma cells and the microbiome can generally be performed in different phases of the cycle. Special tests such as uterine killer cells, on the other hand, require a specifically defined time point in the cycle, in the luteal phase.
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Taking the tissue sample
Using a thin catheter, we take a small sample of the uterine lining. The examination takes only a few minutes and is usually performed on an outpatient basis. Depending on the test, the biopsy is performed, for example, in the first half of the cycle, around ovulation, or specifically in the second half of the cycle.
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Laboratory analysis
Depending on the clinical question, the sample is examined in different ways. Options include histological and immunohistochemical testing for CD138-positive plasma cells, a molecular biological analysis of the endometrial microbiome, or determination of uterine killer cells.
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Discussion of results
Once the results are available, we discuss the findings with you in detail and interpret them together in the context of your medical history and previous fertility treatments. Especially with specialized endometrial investigations, it is important not to assess individual laboratory values in isolation.
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Individual Treatment
If chronic endometritis is confirmed, for example, antibiotic therapy may be appropriate. In the case of microbiome changes or other abnormalities, we assess individually whether this leads to a therapeutic consequence. In doing so, we also take into account the varying scientific evidence for the respective treatment.
Endometrial diagnostics in Munich – individualized and evidence-based
With specialized investigations of the uterine lining, it is not only the laboratory finding that matters, but above all its interpretation in the context of your individual fertility history.
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Time & trust
In a calm, protected atmosphere, we take sufficient time for your questions and concerns—sensitively and on an equal footing, from woman to woman.
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Specialised experience
We have many years of experience in caring for patients with repeated implantation failure, recurrent miscarriages, and complex fertility histories.
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Targeted diagnostics
Not every available test is useful for every patient. We decide individually which endometrial diagnostics can provide additional insights based on your medical history and previous findings.
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Differentiated interpretation of findings
Whether CD138-positive plasma cells, the endometrial microbiome, or specialized additional diagnostics: we do not view results in isolation, but together with your previous treatments and other possible causes.
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Evidence-based counseling
The scientific evidence is not the same for all endometrial investigations. We discuss transparently with you what is well studied, where scientific uncertainties remain, and which therapeutic consequences can reasonably be derived from this.
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Costs of endometrial diagnostics in Munich
In addition, there are costs for the external laboratories that analyze the samples. These services are billed to you directly by the external laboratory.
Make an appointmentNo fixed or flat-rate prices: We bill on the basis of the official scale of fees for doctors (GOÄ). According to the GOÄ, we are not allowed to quote fixed or flat-rate prices for medical services. The prices mentioned are intended to provide orientation and are typical for the treatments mentioned.
Possible VAT liability: Medical services may be subject to VAT (currently 19%). This applies if, after diagnostics have been carried out, no medical indication or confirmed diagnosis is present and it is therefore not a medical treatment in the strict sense. This can be the case in particular with social freezing treatments, but also with the treatment of single moms and same-sex couples.
We would be happy to provide you with detailed cost information for the planned treatment in advance. This allows you to clarify cost coverage with your private health insurance (PKV) as best as possible beforehand. Statutory health insurance (GKV) does not cover costs at our center.
Frequently asked questions about endometrial diagnostics for an unfulfilled wish to have a child
What is chronic endometritis (CE) and what role does it play when trying to conceive?
Chronic endometritis is an inflammation of the uterine lining that usually causes few symptoms or goes unnoticed. It is associated with repeated implantation failure and recurrent miscarriages and can therefore be investigated as a possible additional factor in relevant fertility histories. Because chronic endometritis often does not cause typical symptoms, a targeted examination of the uterine lining is usually required for diagnosis.
How is chronic endometritis diagnosed?
For diagnosis, a small tissue sample is taken from the uterine lining. In the laboratory, it is examined histologically and immunohistochemically. Particularly important is the detection of CD138-positive plasma cells, which may indicate chronic inflammation. Since there is currently no internationally uniform cut-off value for the number of plasma cells, the result should always be assessed together with the medical history and previous fertility treatments.
Can chronic endometritis impair implantation or increase the risk of miscarriage?
Studies show an association between chronic endometritis and lower pregnancy and live birth rates. Its significance is being investigated particularly in cases of repeated implantation failure and recurrent miscarriages. However, whether chronic endometritis is actually the cause of the absence of pregnancy or a miscarriage in an individual case cannot be determined on the basis of the finding alone.
How is chronic endometritis treated?
In cases of clinically relevant chronic endometritis, antibiotic treatment may be appropriate. Depending on the initial findings and the individual situation, a repeat endometrial biopsy may then be performed to check whether the inflammation has resolved. Studies show, in part, higher pregnancy and live birth rates after successfully treated chronic endometritis; however, the evidence is still heterogeneous.
What is the endometrial microbiome?
The endometrial microbiome refers to the totality of microorganisms detectable in the uterus. Studies are currently investigating, in particular, the significance of lactobacilli and other bacteria for the uterine lining, implantation of an embryo, and the course of pregnancy. Unlike the vaginal microbiome, the bacterial load in the endometrium is very low, which makes testing and interpretation particularly challenging.
Can a disrupted uterine microbiome impair implantation?
Some studies show associations between certain changes in the endometrial microbiome and lower implantation, pregnancy, or live birth rates. However, it has not yet been conclusively clarified whether these changes are actually the cause of impaired implantation or are merely associated with it. There are also no generally accepted cut-off values for what an “optimal” endometrial microbiome should look like.
When can a microbiome test be useful when trying to conceive?
Analysis of the endometrial microbiome is not part of routine fertility diagnostics. In selected patients with repeated implantation failure, recurrent miscarriages, or complex fertility histories, it may be discussed as an additional test following individual counseling.
What are uterine killer cells and what is their significance when trying to conceive?
Uterine natural killer cells (uNK cells) are a normal and important component of the immune system of the uterine lining. Among other things, they are involved in implantation and early placental development. Whether an increased number or altered activity of these cells causes repeated implantation failure or miscarriages has not yet been clearly established.
How is an endometrial biopsy performed, and is it painful?
For an endometrial biopsy, a thin catheter is inserted through the cervix into the uterus and a small sample of the uterine lining is taken. The procedure usually takes only a few minutes and can be performed on an outpatient basis. During sampling, short-term menstrual-like pain or cramps may occur. Anesthesia is generally not required.
When in the cycle is an endometrial biopsy performed?
The optimal time depends on which endometrial investigation is planned. Testing for chronic endometritis or CD138-positive plasma cells can generally be performed in different phases of the cycle. For other tests, timing is more important: uterine killer cells are typically examined in the second half of the cycle. We therefore plan the timing of the biopsy individually according to the specific clinical question.
How much do endometrial diagnostics cost, and does health insurance cover the costs?
The costs depend on which investigations are performed. In addition to the endometrial biopsy, costs may arise for histological, immunohistochemical, or molecular biological analyses—for example, for CD138-positive plasma cells, the endometrial microbiome, or uterine killer cells. As a rule, these specialized investigations are not covered by statutory health insurance. With private health insurance, possible reimbursement depends on the medical indication and the individual plan. We will, of course, inform you of the expected costs before the examination.
