The association between menstrual irregularities and hypothyroidism is described in literature: the hypothalamic-pituitary-thyroid axis and the hypothalamic-pituitary–gonadal axis work together, and any dysfunction in the thyroid can affect the serum sex steroid levels, sex hormone-binding globulin (SHBG), gonadotropin-releasing hormone (GnRH) and prolactin [7]. This evidence concerns the gene SHBG and hypothyroidism.