Endometriosis Linked to Higher Risk of Thyroid Disorders; ACOG Issues New Diagnostic Guidance

Women with endometriosis have a higher long-term risk of developing thyroid disorders, including Graves disease and hypothyroidism, independent of treatment type, according to study results published in Maturitas journal. The American College of Obstetricians & Gynecologists (ACOG) has released new clinical guidance on endometriosis diagnosis, aiming to reduce the four to 11 years patients typically wait from symptom onset to diagnosis.

The retrospective cohort study used data from the TriNetX global Collaborative Network, a federated real-world database of deidentified electronic medical records from more than 80 healthcare organizations. Patients aged 21 to 60 years with endometriosis who had received surgical or pharmacologic treatment were included in the endometriosis cohort, whereas women without endometriosis who had undergone gynecological examinations and pelvic ultrasonography were in the comparator group. Patients with preexisting metabolic, cardiovascular, autoimmune, or thyroid conditions were excluded from the study.

After propensity score matching, 59,180 patients were included in each group, yielding a total of 118,360 participants. The study period spanned January 1, 2001, through December 31, 2020, with follow-up of up to 20 years.

Over follow-up, the endometriosis cohort demonstrated higher risks for hypothyroidism (hazard ratio 1.19; 95% CI, 1.13-1.25), hyperthyroidism (HR, 1.21; 95% CI, 1.09-1.35), Graves disease (HR, 1.27; 95% CI, 1.04-1.56), nontoxic goiter (HR, 1.31; 95% CI, 1.23-1.39), and thyroiditis overall (HR, 1.32; 95% CI, 1.18-1.48). Patients with endometriosis also had increased risks for acute thyroiditis (HR, 2.38; 95% CI, 1.01-5.63), subacute thyroiditis (HR, 1.99; 95% CI, 1.04-3.81), and Hashimoto thyroiditis (HR, 1.32; 95% CI, 1.17-1.50).

Patients with endometriosis also had increased risks for structural thyroid outcomes, including malignant neoplasm of the thyroid gland (HR, 1.55; 95% CI, 1.21-1.97) and benign neoplasm of the thyroid gland (HR, 2.47; 95% CI, 1.73-3.52). Among women with endometriosis, surgical vs nonsurgical management was not associated with significant differences in thyroid outcomes.

Endometriosis is a chronic gynecological condition affecting approximately 2% to 10% of women of reproductive age and is characterized by dysmenorrhea, nonmenstrual pelvic pain, and infertility. Prior systematic reviews have reported increased risks for coexisting autoimmune diseases, including autoimmune thyroid disease, among women with endometriosis.

ACOG released Clinical Practice Guideline 11: "Diagnosis of Endometriosis" ahead of Endometriosis Awareness Month in March and in advance of additional guidance that ACOG is developing on the management of endometriosis. Endometriosis is a chronic inflammatory disorder defined by the presence of endometrial-like tissue lesions outside the uterus. Women and girls with endometriosis may experience chronic pain, infertility, and decreased health-related quality of life.

Diagnostic delay is a significant issue in endometriosis care, with people waiting between four and 11 years on average from the onset of symptoms to receipt of diagnosis. While patients are waiting for a diagnosis, they can experience disease progression, onset of new symptoms, further decline in quality of life, and increasing health care costs. The traditional reliance on surgical findings to diagnose endometriosis is an important contributor to diagnostic delays.

To help reduce delays in endometriosis care, ACOG's new guidance provides detailed recommendations on the use of clinical findings and imaging tests to provide a presumptive diagnosis of endometriosis. A presumptive diagnosis of endometriosis based on patient history, symptoms, and physical examination findings allows clinicians to offer patients empiric medical treatment while continuing the evaluation process with imaging studies, enabling patients to feel better faster and connect them with resources and support sooner.

The new guidance also addresses barriers to endometriosis care arising from racial bias and gender-identity bias, highlighting that people from marginalized communities may experience additional delays in diagnosis and treatment. Delays in care can be due to inadequate training in the recognition of endometriosis, resulting in dismissal, normalization, or misattribution of patients' symptoms.

ACOG's new guidance emphasizes the importance of shared decision making in endometriosis care. Patients with endometriosis may have different goals, depending on their symptoms, reproductive plans, and personal priorities. Some patients may choose surgery to diagnose and treat endometriosis, while others may prefer empiric medical management based on symptoms or imaging.

Study limitations include the use of aggregated data without access to individual-level records, as well as the lack of detailed clinical information such as endometriosis severity and thyroid laboratory values. The findings underscore the importance of ongoing thyroid function monitoring and clinical awareness in women with endometriosis.