Unexplained infertility often appears without clear diagnostic answers in standard fertility evaluation; these evaluations may miss endometrial dysfunction that leads to implantation failure and recurrent pregnancy loss. Endometrial biomarker testing finds inflammatory conditions by detecting protein markers instead of relying only on imaging or blood tests. Here are a few benefits of testing in unexplained infertility:
Improving Unexplained Infertility Diagnosis
Standard unexplained infertility testing evaluates hormone levels, ovulation patterns, tubal structure, and uterine anatomy without analyzing molecular activity inside the endometrium. Implantation dysfunction can remain undetected in many unexplained infertility cases despite normal routine testing results; endometrial biomarker analysis helps to identify biologic abnormalities that imaging and bloodwork do not detect. A uterus biopsy collects a small tissue sample from the uterine lining during the menstrual cycle. Laboratory analysis then evaluates BCL6 expression linked to inflammation and CD138 staining associated with plasma cells linked to chronic infection.
Detecting Silent Endometriosis
Endometriosis-related inflammation is sometimes present even when there is no pelvic pain and when ultrasound or other imaging tests appear normal. Because of this, some fertility issues may not be detected through standard testing. BCL6 is a protein involved in inflammation and immune activity in the uterine lining, or endometrium. Some tests reveal elevated BCL6 levels; this suggests the presence of inflammation in the uterus that could affect implantation and fertility.
An endometrial biopsy may be used to examine tissue-level activity more closely, including testing for BCL6. The biopsy at some fertility clinics is performed during a single visit. It is also a timed biopsy; the sample is collected between seven and ten days after ovulation. The biopsy results allow doctors to better understand possible reasons for unexplained infertility or repeated implantation failure.
Evaluating Progesterone Response
Successful implantation depends on the uterine lining responding properly to progesterone during the second half of the menstrual cycle. Progesterone resistance develops when the endometrium does not respond normally to this hormone, and a poor response disrupts preparation for implantation. Changes in progesterone response affect the timing and activity needed for embryo attachment inside the uterus.
Implantation problems then develop even when ovulation and embryo growth appear normal; this disruption contributes to unexplained infertility and repeated implantation failure. Elevated BCL6 levels provide insight into progesterone-response problems inside the uterine lining. Inflammation linked to BCL6 interferes with progesterone-related activity, and pregnancy-supporting functions may become weaker during the implantation window. Testing during this stage of the cycle helps identify hormone-response problems that affect implantation.
Identifying Causes of Implantation Failure
Repeated implantation failure has multiple causes, including embryo and uterine factors, as well as inflammation or infection. These issues may not be visible on ultrasounds, so additional endometrial testing is often required. Identifying whether there is abnormal BCL6 expression in the uterine lining helps reveal why previous implantation attempts have failed. When doctors evaluate this biomarker, they may find hidden symptoms of unexplained infertility. Patients are also able to better understand possible reasons for repeated implantation failure, allowing them to make more informed decisions and plan customized treatment plans with their fertility specialists.
Detecting Chronic Endometritis
Chronic endometritis is a condition involving ongoing low-grade inflammation in the uterine lining. It is often associated with an imbalance of bacteria or a persistent infection, but for some patients, the exact cause is not obvious. This condition is difficult to detect with standard fertility tests because ultrasound and other imaging studies usually appear normal. For this reason, it may go unnoticed during routine infertility evaluation.
One of the main ways to identify chronic endometritis is through an endometrial biopsy. In the laboratory, the tissue is stained using a marker called CD138, which highlights plasma cells. These cells are part of the immune system, and their presence may indicate chronic endometriosis. When the cells are present above normal levels, it indicates potential ongoing inflammation consistent with chronic endometritis.
Get Support for Unexplained Infertility
Persistent infertility often develops from hidden problems inside the uterine lining. Tissue-based biomarker testing helps identify inflammation, progesterone-response issues, and chronic infection affecting implantation. Endometrial evaluation also improves understanding of repeated implantation failure through direct analysis of uterine receptivity. Book a fertility consultation to review your diagnostic options and use advanced testing to confirm a diagnosis of unexplained infertility or rule out certain conditions.
