Prevalence of Subclinical Hypothyroidism in Women With Abnormal Uterine Bleeding

Background: Abnormal uterine bleeding is a common gynecological condition among women of reproductive age and is frequently associated with endocrine disorders, particularly thyroid dysfunction. Subclinical hypothyroidism has been increasingly recognized as a potential contributor to menstrual irregularities. Objectives: To determine the prevalence of subclinical hypothyroidism among women presenting with abnormal uterine bleeding and to evaluate its association with different clinical patterns of abnormal uterine bleeding and selected demographic factors. Methods: This cross-sectional study was conducted at Um Al-Baneen Private Hospital in Baghdad from September 2023 to December 2025. A total of 120 women aged 18–45 years presenting with abnormal uterine bleeding were included. Serum thyroid-stimulating hormone and free thyroxine levels were measured to assess thyroid function. Subclinical hypothyroidism was defined as elevated thyroid stimulating hormones with normal thyroxin levels. Data were analyzed using descriptive statistics, chi-square test, and logistic regression analysis, with a p-value <0.05 considered statistically significant. Results: The mean age of participants was 31.6 ± 6.4 years, and the mean BMI was 28.1 ± 4.8 kg/m². Subclinical hypothyroidism was detected in 22 patients (18.3%), while 86 (71.7%) were euthyroid. Menorrhagia was the most common bleeding pattern (43.3%) and showed a significant association with subclinical hypothyroidism (p = 0.041). Women with SCH were significantly older than non-SCH participants (33.8 ± 5.9 vs 31.1 ± 6.5 years, p = 0.048). Logistic regression analysis revealed that age >30 years (OR = 1.94, 95% CI: 1.02–3.68, p = 0.042) and menorrhagia (OR = 1.73, 95% CI: 1.01–3.45, p = 0.039) were significant predictors of SCH, while BMI was not significantly associated. Conclusion: Subclinical hypothyroidism is relatively prevalent among women with abnormal uterine bleeding and is significantly associated with menorrhagia and increasing age. These findings highlight the importance of routine thyroid function screening in women presenting with abnormal uterine bleeding, as early detection and management of subclinical hypothyroidism may improve clinical outcomes.