The Impact of Polycystic Ovarian Syndrome on Gestational Diabetes

When Stein and Leventhal, in 1935, observed a group of women who suffered from sterility, oligomenorrhoea, or amenorhhoea, hirsutism, and enlarged polycystic ovaries, the disorder that became known as the polycystic ovarian syndrome (PCOS) or the Stein-Leventhal syndrome, was diagnosed for the first time (Stein, 1958). The variability of individual presentation, as well as a varying collection of signs and characteristic features, with no single diagnostic test justify the categorization of the PCOS as a syndrome that affects not only reproductive health, but also the metabolic and cardiovascular systems. Although PCOS is one of the most common endocrinopathies in women, with an incidence of about 510% throughout the reproductive age span (Metalliotakis, 2006), there are divergent opinions about how to define and diagnose PCOS, as well as different types of treatment options throughout Europe and the US (Badawy & Elnashar, 2011). The high prevalence of women with this endocrine disorder highlights the importance of understanding the clinical presentation, pathophysiology, associated disorders, and treatment options. Up to 40% of women of reproductive age with PCOS have Type 2 diabetes or an impaired glucose tolerance (Legro et al., 2005), a form of insulin resistance that occurs equally in obese, normal weight, and thin women with PCOS (Matalliotakis et al., 2006). PCOS has been associated with an increased risk for gestational diabetes mellitus (GDM), but solid evidence confirming PCOS as a risk factor for GDM is still missing (Toulis et al., 2009). GDM, a wellknown state of carbohydrate intolerance with a high, and rising, prevalence, causes not only maternal but also fetal pregnancy complications. GDM has a presentation similar to PCOS, and both are considered risk factors for Type 2 diabetes mellitus (Retnakaran et al., 2008). The aim of this review is to summarize the available evidence about the risk of impaired glucose tolerance and GDM in PCOS women, as well as to review the pathophysiological aspects. In addition, the potential beneficial influence of several PCOS-specific treatment options on PCOS and GDM will be discussed.