Endometriosis and polycystic ovary syndrome (PCOS) are common gynecological disorders that constitute a significant burden of disease in women of fertile age. The disorders share a link to female reproduction and infertility; however, divergent effects on menstrual cycle, related hormones, and body composition have been proposed. Disorders of the thyroid gland including abnormal thyroid dysfunction (hyperthyroidism or hypothyroidism) and/or markers of thyroid autoimmunity similarly show a female predominance and onset in younger age groups. We reviewed the literature on the association between endometriosis, PCOS, and thyroid disease up until July 1, 2023, and identified 8 original studies on endometriosis and thyroid disease and 30 original studies on PCOS and thyroid disease. The studies were observational and heterogeneous regarding the design, sample size, and definitions of exposure and outcome; however, a tendency was seen toward an association between hyperthyroidism and endometriosis. Especially an association between endometriosis and slightly elevated levels of thyroid-stimulating hormone receptor antibodies has been found and corroborated in studies from different populations. On the other hand, the literature review turned a focus toward an association between hypothyroidism and PCOS, however, with uncertainties as to whether the association is caused by hypothyroidism per se and/or the thyroid autoantibodies (thyroid peroxidase and thyroglobulin antibodies). More evidence is needed to substantiate an association between endometriosis, PCOS, and thyroid disease, and to differentiate between the role of thyroid function and thyroid autoimmunity. Furthermore, studies are warranted to extend knowledge on the different disease characteristics and underlying mechanisms.

子宫内膜异位症和多囊卵巢综合征（PCOS）是常见的妇科疾病，对育龄妇女构成重大的疾病负担。这些疾病与女性生殖和不孕不育有关；然而，人们提出了对月经周期、相关激素和身体成分的不同影响。甲状腺疾病，包括异常甲状腺功能障碍（甲状腺功能亢进或甲状腺功能减退）和/或甲状腺自身免疫标志物，同样显示出女性占主导地位，并且在较年轻的年龄组中发病。我们回顾了截至 2023 年 7 月 1 日有关子宫内膜异位症、PCOS 和甲状腺疾病之间关联的文献，并确定了 8 项关于子宫内膜异位症和甲状腺疾病的原始研究以及 30 项关于 PCOS 和甲状腺疾病的原始研究。这些研究在设计、样本量以及暴露和结果的定义方面都是观察性的和异质性的；然而，人们发现甲状腺功能亢进症和子宫内膜异位症之间存在关联。特别是子宫内膜异位症与促甲状腺激素受体抗体水平轻微升高之间的关联已在不同人群的研究中被发现并得到证实。另一方面，文献综述将焦点转向甲状腺功能减退症与 PCOS 之间的关联，但不确定这种关联是否由甲状腺功能减退症本身和/或甲状腺自身抗体（甲状腺过氧化物酶和甲状腺球蛋白抗体）引起。需要更多的证据来证实子宫内膜异位症、多囊卵巢综合征和甲状腺疾病之间的关联，并区分甲状腺功能和甲状腺自身免疫的作用。此外，有必要进行研究以扩展对不同疾病特征和潜在机制的了解。