TG and polycystic ovary syndrome: Polycystic ovary syndrome (PCOS) is the most common gynecological endocrine disease in the reproductive age of women, with an incidence of 5% to 10% in European and American countries, and the prevalence rate in China is 5.61%.[1–3] The thyroid hormone plays an important role not only in endocrine and metabolic regulation but also in reproductive health.