Patterns of Thyroid Dysfunction among Women with Menstrual Disorder

Background and objectives: Thyroid dysfunction can lead to menstrual irregularities and infertility. Thus, this study aimed to assess the frequency and patterns of thyroid dysfunction in patients with menstrual disorders. Methods: This prospective cross-sectional study was conducted at Shar Teaching Hospital, from June 01, 2023, to June 01, 2024, on 200 women with menstrual abnormality. Their thyroid hormone levels were estimated and the correlations between patients’ age, type of thyroid dysfunction, and menstrual abnormality were determined. Results: The mean age of women was 32.14 ± 7.6 years, and most of them were aged 31– 40 years (41.5%) with irregular menses (n=76). Women aged 31- 40 years had the highest incidence of menstrual abnormality (n=83), of which most cases were irregular menses (42.1%). Most patients had thyroid disorder (n=128), of which subclinical hypothyroidism reported the highest level (n=67). The highest mean level of thyroid stimulating hormone was found in patients with amenorrhea (20.81 ± 33.6 µIU/mL), free tri-iodo tyrosin in oligomenorrhea (3.35 ± 1.0 pg/dL) (p=0.02 and p=0.002, respectively) and free tetra-iodo tyrosin in both oligomenorrhea and irregular menses (1.20 ± 0.5 ng/dL). The vast majority of patients had positive anti-thyroid peroxidase antibody (51.5%) and negative thyroid stimulating hormone receptor binding antibody (91%) (p>0.05). Conclusions: Subclinical hypothyroidism is common among patients with menstrual abnormalities, especially young adults. Thyroid-stimulating hormone and free tri-iodo tyrosin were directly associated with menstrual abnormalities, while both anti-thyroid peroxidase antibody and thyroid-stimulating hormone receptor binding antibody were not.