POLYCYSTIC OVARY SYNDROME: ORIGINS AND IMPLICATIONS: Maternal complications of pregnancy in polycystic ovary syndrome

In brief: PCOS leads to an increased risk of pregnancy complications, and immunological factors are strongly implicated in both PCOS and pregnancy complications. This review discusses the leading theories for this connection, including placental dysregulation, insulin resistance, excess androgens, and a preexisting pro-inflammatory state in PCOS. Abstract: Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders, often contributing to infertility and significantly increasing chances of maternal complications in pregnancy. PCOS is commonly diagnosed based on hyperandrogenism, oligo-ovulation or anovulation, and polycystic ovarian morphology. Insulin resistance and obesity are common comorbidities, which may also contribute to maternal complications. Specifically, PCOS is a risk factor for preterm birth, gestational hypertension, gestational diabetes mellitus, and fetal growth restriction, although the mechanism by which PCOS contributes to these conditions is not well understood and may vary by condition. Here, we review the immunological features of PCOS in both the pregnant and non-pregnant state, and we highlight a potential role for the placenta and poor decidualization in increasing the risk of pregnancy complications. We also summarize how the chronic inflammation seen in PCOS mirrors that observed in several pregnancy complications, as well as how insulin resistance and hyperandrogenism in PCOS contribute to these complications.