Polycystic ovarian syndrome (PCOS) affects up to 18% of women internationally, with widespread effects on their reproductive, metabolic and cardiovascular health. To date, the etiology of this syndrome remains unclear. Patterns of expression within family groups suggest a genetic inheritance but neither a clear inheritance pattern nor candidate gene(s) has been discovered to date. Animal studies have proven that in utero exposure to high levels of androgen can elicit PCOS-like traits in various mammals, including rhesus monkeys who share a similar reproductive biology with humans. An alternate mechanism for etiology is the epigenetic alteration in programming of the fetal ovaries in response to androgen exposure. This chapter summarizes the evidence available and hypothesizes possible mechanisms of action via which PCOS could be transmitted from an affected mother to her offspring. The origins of androgens in the fetal circulation as well as the role of AMH and luteinizing hormone (LH) are discussed as are the actions of the placenta and the difference in placental function and hormone secretion patterns in PCOS females compared to “normal” physiology.

Anti-Müllerian hormone (AMH) has recently been proposed as a diagnostic marker for polycystic ovary syndrome (PCOS) instead of polycystic ovarian morphology (PCOM) seen on ultrasound. As serum AMH level reflects excess small follicles not visible on ultrasonography, AMH level would theoretically be more accurate than PCOM as a diagnostic marker. Its value is significantly higher in PCOS patients than in normal women; its high levels are also considered to play an important role in the pathogenesis of the disorder, accounting for anovulation in PCOS patients. Nevertheless, its use is still not recommended by the international guidelines as an alternative for detecting PCOM or as a single test result for the diagnosis of PCOS. Its potential clinical applications in PCOS patients are currently the characterization of the severity of the syndrome and in deciding hormone doses for ovarian stimulation treatments. An international standard is needed to standardize the existing assays for AMH calibration before diagnostic cutoffs can be determined and before AMH use as a diagnostic marker can be considered meaningful.