Just a Spit-Test Away: Changing the Tone of Endometriosis Diagnoses for Women
Introduction
Endometriosis is a common condition among premenopausal women across the world, yet it is vastly underresearched and often tedious to get treated for. The only way to get a definitive diagnosis until recently was laparoscopic surgery to identify endometrial lesions, which would then be biopsied [1]. Though a minimally invasive surgery, patients usually experience some level of discomfort after getting a laparoscopy. To mitigate these issues, an exciting new diagnostic tool has been developed and already implemented as standard in a few countries across the world: the Ziwig Endotest.
What is Endometriosis?
Background
Endometriosis is a condition that affects around 1 in every 10 women around the world and is usually diagnosed in women between 20 and 30 years of age [1]. However, it is common practice for women to go an average of 4 to 11 years from symptom onset without an accurate diagnosis, mainly because of systemic imbalances that overlook the importance of maintaining gynecological health in female populations [2, 3]. Most complications of endometriosis are debilitatingly painful, meaning the prolonged waiting period and general lack of knowledge often result in drastic declines in quality of life for affected women [3]. Additionally, until recently, the standard for diagnosing endometriosis within the USA was through invasive exploratory surgery and biopsy of the endometrial lesions [3, 4]. So, not only do affected women wait nearly a decade before diagnosis, but most also have to endure invasive procedures to definitively diagnose something that, based on symptoms alone, should have been quickly recognized and treated [3, 5]. Overall, the system’s disinterest in endometriosis is a reminder of why advocating for equity in healthcare is crucial to getting female patients the care they deserve.
The Endometrial Tissue: Form and Function
To understand endometriosis, we first need to understand the endometrial tissue. The endometrial lining, also known as the uterine lining, is the membrane that lines the inside of the uterus. The main function of the endometrium is to provide an implantation site for fertilized eggs and sustain the resulting pregnancy [6]. When pregnancy does not occur, the lining is shed through the process known as menstruation. The lining is regularly shed and regenerated during menstruation, with it being regenerated an average of 400 times in premenopausal women [6]. The endometrium can be further broken down into the basal (bottom) and functional (top) layers. The basal layer attaches to the smooth muscle layer of the uterus, also known as the myometrium. The functional layer serves as the implantation site for fertilized eggs, maintains a pregnancy once implantation is successful, and is shed if implantation does not occur. For this cycle to occur properly, the ovaries produce the hormones progesterone and estradiol, which are closely regulated throughout each phase of the menstrual cycle [6].
Endometriosis is Defined by Disordered Tissue Growth
Endometriosis is defined as a condition where tissue similar to the uterine lining grows elsewhere within the body [2, 4]. The most common areas where this growth can occur are the space behind the uterus, the myometrium (the smooth muscle of the uterus), the ovaries, the fallopian tubes, and the peritoneum (the smooth tissue lining the abdominal cavity). Tissue growth can also occur in other areas such as the vagina or intestines, but such instances are rare [1]. The presence of the abnormal tissue outside the uterine cavity leads to the disruption of the hormones progesterone and estradiol, commonly resulting in progesterone resistance and estradiol dominance [7]. These hormones are directly tied to the endometrium's ability to implant an embryo, causing most affected women to struggle with infertility. . The disruption of these hormones is likely also a contributing factor to the chronic inflammation and pain most patients face [7]. Common symptoms of endometriosis are mild to intense pelvic pain, severe menstrual cramps, abdominal/back pain during or between periods, abnormally heavy bleeding during periods, pain during sex, pain during urination or bowel movements, and consistent stomach problems (e.g., diarrhea, constipation, bloating). If left untreated, the irregular tissue can lead to the formation of cysts, adhesions, and scar tissue, often leading to lasting pain [1].
The Ziwig Endotest: Separating Discomfort from Diagnosis
The Ziwig Endotest is a saliva-based diagnosis method that uses a specific miRNA signature within a person’s saliva to detect if they are affected with endometriosis [8]. MicroRNAs, miRNAs for short, are non-coding RNAs (meaning that they are not used to synthesize proteins) that help regulate how our genes are expressed [9]. This signature miRNA was isolated by comparing samples from women with endometriosis to samples of those who were not affected. With this technology, collecting a sample of a patient’s saliva would be all that is needed to get a diagnosis within just a couple of days. Initial statistical analysis shows excellent diagnostic performance, yielding a high percentage of accurate results [8]. It should be noted that though there are different stages of endometriosis, this test cannot differentiate between specific stages as it is simply testing for markers in saliva. However, the drastic reduction in waiting time alongside the option to bypass an invasive diagnostic procedure is a step forward for women’s health. Accessibility to this technology is the next step to conquer — as this technology is still new, it is not yet available in the USA and is still relatively expensive in the countries where it is available. However, the development of a tool that can diagnose endometriosis through a non-invasive procedure is an exciting step in the right direction toward cultivating comfortable medical environments for women.
Why does this matter?
The treatment that we, as women, receive in healthcare environments is dependent on not only the capability of our doctors, but also our abilities for self-advocacy. The decade-long wait times, invasive procedures, and chronic pain that many women have had to live with just for a diagnosis of endometriosis is unacceptable — and the lack of research into endometriosis is even more so. This atmosphere of indifference, combined with the preexisting stigma that surrounds female-centric health issues, supports the broken system that forces pain-ridden women to wait years for a diagnosis. In addition, the existing system drastically impacts quality of life in a multitude of ways because of its inefficiency. To challenge these systemic inequities, it falls on us to advocate for better treatment practices, with an emphasis on accuracy, efficiency, and comfort for patients. However, until recently, no feasible alternative existed for patients to turn to. This is why the Ziwig Endotest is such an exciting development for female reproductive health. It provides an alternative pathway to diagnosis that does not involve laparoscopies, biopsies, and a decade of wait times, prioritizing patients instead of conforming to an indifferent system.
References
Cleveland Clinic [Internet]. [cited 2026 Jul 18]. What is endometriosis? Available from: https://my.clevelandclinic.org/health/diseases/10857-endometriosis
Hudson N. The missed disease? Endometriosis as an example of ‘undone science.’ Reprod Biomed Soc Online. 2021 Aug 13;14:20–7. doi:10.1016/j.rbms.2021.07.003 PubMed PMID: 34693042; PubMed Central PMCID: PMC8517707.
New endometriosis guidelines: A smoother path to effective treatment | Women’s Health | Your Pregnancy Matters | UT Southwestern Medical Center [Internet]. [cited 2026 Jul 19]. Available from: https://utswmed.org/medblog/endometriosis-diagnosis-treatment/
Mayo Clinic [Internet]. [cited 2026 Jul 19]. Endometriosis. Available from: https://www.mayoclinic.org/diseases-conditions/endometriosis/diagnosis-treatment/drc-20354661
ACOG Publishes New Endometriosis Clinical Guidance, Aiming to Shorten Time to Diagnosis and Improve Access to Care [Internet]. [cited 2026 Jul 20]. Available from: https://www.acog.org/news/news-releases/2026/02/acog-publishes-new-endometriosis-clinical-guidance-aiming-shorten-time-diagnosis-improve-access-care
Cleveland Clinic [Internet]. [cited 2026 Jul 17]. What is the endometrium? Available from: https://my.clevelandclinic.org/health/body/endometrium
Marquardt RM, Kim TH, Shin JH, Jeong JW. Progesterone and estrogen signaling in the endometrium: what goes wrong in endometriosis? Int J Mol Sci. 2019 Aug 5;20(15):3822. doi:10.3390/ijms20153822 PubMed PMID: 31387263; PubMed Central PMCID: PMC6695957.
Bendifallah S, Dabi Y, Suisse S, Delbos L, Spiers A, Poilblanc M, et al. Validation of a Salivary miRNA Signature of Endometriosis — Interim Data. NEJM Evidence. 2023 Jun 27;2(7). doi:10.1056/EVIDoa2200282
O’Brien J, Hayder H, Zayed Y, Peng C. Overview of MicroRNA Biogenesis, Mechanisms of Actions, and Circulation. Front Endocrinol (Lausanne). 2018 Aug 3;9:402. doi:10.3389/fendo.2018.00402 PubMed PMID: 30123182; PubMed Central PMCID: PMC6085463.
Comments