that metformin had no effect on maternal androgens in pregnancies occurring in the setting of PCOS. One systemic review suggested that polymorphisms in the vitamin D receptor gene are associated with the prognosis of polycystic ovary syndrome, though this is based on small sample sizes and is debated. Studies have shown benefits for vitamin D supplementation in women with vitamin D deficiency and PCOS. Hyperinsulinemia can increase the production of androgens in the ovaries. One context in which this occurs is HAIR-AN syndrome, a rare subtype of PCOS. Hyperthecosis and hyperinsulinemia Hyperthecosis occurs when the cells of the ovarian stroma transition from interstitial cells, located between other cells, into luteinized theca cells. Theca cells are located in the ovarian follicles and become luteinized when the ovarian follicle bursts and a new corpus luteum is formed. The dispersal of luteinized theca cells throughout the ovarian stroma — in contrast to their distribution in PCOS, in which luteinized theca cells occur around cystic follicles only — causes women with hyperthecosis to have higher testosterone levels and virilization) than women with PCOS. Elevated insulin is also characteristic of hyperthecosis. Hyperthecosis most commonly develops in postmenopausal women and is linked to acne, hirsutism, growth of the clitoris, baldness, and voice deepening. Obesity can play a role in insulin resistance. It makes thecal cells more responsive to luteinizing hormone. Therefore, obesity increases ovarian androgen production. Additionally, obesity elevates inflammatory adipokines which leads to not only adipogenesis, but also heightened insulin resistance. Cushing’s syndrome Cushing's syndrome develops as a result of long-term exposure to the hormone cortisol. Cushing's syndrome can either be exogenous or endogenous, depending on whether it is caused by an external or internal source, respectively. The intake of glucocorticoids, a type of corticosteroid, is a common cause for the development of exogenous Cushing's syndrome. Endogenous Cushing's syndrome can occur when the body produces excess cortisol. This occurs when the hypothalamus of the brain signals to the pituitary gland with excess corticotropin-releasing hormone, which in turn secretes adrenocorticotropin hormone (ACTH). ACTH then causes the adrenal glands to release cortisol into the blood. Signs of Cushing's syndrome include muscle weakness, easy bruising, weight gain, male-pattern hair growth (hirsutism), coloured stretch marks, and an excessively reddish complexion in the face. Cushing's syndrome can cause androgen excess and hence the signs and symptoms of hyperandrogenism. Congenital adrenal hyperplasia Congenital adrenal hyperplasia (CAH) describes a group of autosomal