Is foetal hyperexposure to androgens a cause of PCOS?

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting reproductive-aged women. The pathophysiology of this syndrome is still not completely understood but recent evidence suggests that the intra-uterine environment may be a key factor in the pathogenesis of PCOS, in particular, hyperexposure of the foetus to androgens. High concentrations of maternal serum testosterone during pregnancy have been shown to influence behaviour during childhood, the prevalence of autism disorders and anti-Mullerian hormone (AMH) concentrations in adolescence. They are also thought to re-programme the female reproductive axis to induce the features of PCOS in later life: oligo/anovulation, polycystic ovaries, hyperandrogenism and insulin resistance (IR). Support for this developmental theory for the aetiology of PCOS is gathering momentum, following results from first animal studies and now human data, which lend credence to many aspects of this hypothesis.