THYROID DYSFUNCTION AND MENSTRUAL IRREGULARITIES IN INFERTILE WOMEN: A COMPARATIVE ANALYSIS OF HORMONAL PROFILES

Abstract

Infertility, defined as the inability to conceive after ≥12 months of unprotected intercourse, affects 5–15% of couples globally, with thyroid dysfunction increasingly recognized as a contributor to reproductive impairment. Thyroid hormones (T3, T4) and thyroid-stimulating hormone (TSH) regulate ovarian function, follicular development, and endometrial receptivity, with imbalances linked to menstrual irregularities, ovulatory dysfunction, and implantation failure. This case-control study investigated thyroid profiles and menstrual patterns in 100 married women (18–55 years), categorized into primary infertility (n=40), secondary infertility (n=10), and controls (n=50). Blood samples were analyzed via chemiluminescence immunoassay (CLIA) for T3, T4, and TSH, and menstrual regularity was assessed through clinical histories. Menstrual irregularities were significantly more prevalent in infertile groups: 62.5% of primary infertility cases exhibited oligomenorrhea (15/40) or amenorrhea (10/40), and 80% of secondary infertility cases reported oligomenorrhea (7/10), compared to 88% regular cycles in controls. Thyroid analysis revealed comparable T3 levels across groups (controls: 6.16±1.63; primary: 6.41±2.81; secondary: 6.14±2.81; p=0.812). T4 levels were numerically lower in infertility groups (19.17±8.09) versus controls (22.41±5.77; p=0.354), while TSH levels were elevated in infertility groups (4.47±1.59) compared to controls (3.11±1.48; p=0.69), though neither reached statistical significance. The findings underscore a high prevalence of menstrual irregularities in infertile women and suggest trends toward subclinical thyroid dysfunction, particularly elevated TSH, which may disrupt reproductive physiology.