Introduction: More than 186 million people suffer to infertility worldwide. Polycystic ovary syndrome (PCOS) is the most common cause of chronic anovulation and infertility. PCOS is known as an endocrine disorder in women of marriageable age and is associated with metabolic disorders and dysfunction of the reproductive system. There is also a clear link between fertility and hypothyroidism, which is often associated with ovulation disorders. In recent years, an increasing zest has been witnessed in conducting more research into PCOS and hypothyroidism. So, recognizing the relationship between these two diseases can help for a better understanding of infertility.Methods: In line with such calls for more research, the present study is aimed at investigating the levels of oxidants and antioxidants in the blood of rats with PCOS induced by estradiol valerate (2 mg/kg of body weight) for 60 days and then received oral propylthiouracil in different doses (1,2 and 4 mg/kg of body weight) to induce hypothyroidism. Results: Results showed an increase in catalase (CAT), superoxide dismutase (SOD) and nitric oxide (NO) in PCOS rats. The results also indicated a significant increase in NO (P < 0.05) and a significant decrease in SOD and CAT (P < 0.05) after hypothyroidism in rats with PCOS. That is, as the severity of the disease increased, these indicators also showed significant alterations. Conclusion: Hence, hypothyroidism following PCOS exacerbates oxidant and antioxidant imbalances in the body, which can eventually result in tissue damage.

Introduction Endocrine disorders such as polycystic ovary syndrome (PCOS) and hypothyroidism can cause infertility. There are evidence that they happen jointly in some circumstances. It still remains unknown, how these two illnesses interact and influence the body. Methods Accordingly, a five‐group was designed, first is the control group, followed by the PCOS group. Estradiol valerate (EV) induced PCOS, the second group had only PCOS and the third, fourth and fifth groups were given varied dosages of propylthiouracil (PTU) to cause hypothyroidism after induction of PCOS. Steroidogenic acute regulatory protein (StAR) expression was measured in the ovaries, and serum was obtained to determine testosterone levels, as well as superoxide dismutase (SOD) as an antioxidant and malondialdehyde (MDA) as an oxidant. Results Based on radioimmunoassay data, testosterone levels were significantly higher in the PCOS group than the control group, and significantly lower (p ˂ .05) in PTU groups comparing with the PCOS group. According to the quantitative real‐time polymerase chain reaction (qRT‐PCR) data, the same results were obtained for the StAR gene as well. The data also indicated a positive correlation between these two. Although both oxidant and antioxidant level increased in PCOS group compared than control group, after hypothyroidism, oxidant level increased significantly (p ˂ .05), meanwhile antioxidant level decreased significantly (p ˂ .05). Conclusions The results of this study illustrate that the presence of both PCOS and hypothyroidism alters the situation more than just PCOS. They also indicate that this situation is associated with imbalanced oxidative/antioxidative status.