Polycystic ovary syndrome and hyperglycaemia in pregnancy. A narrative review and results from a prospective Danish cohort study

BACKGROUND:Insulin resistance is common in polycystic ovary syndrome (PCOS). PCOS may be associated with increased risk of gestational diabetes mellitus (GDM). OBJECTIVES:To (1) review literature regarding PCOS and hyperglycaemia in pregnancy and (2) present original data from Odense Child Cohort (OCC) regarding GDM in PCOS. METHODS:Literature search including original studies from 2000-18. OCC included 2548 pregnant women, 9.5% (n = 241) had PCOS. Fasting plasma glucose was measured in 1519 and 659 oral glucose tolerance tests were performed (with risk factor for GDM, n = 384, without risk factors, n = 275), applying two different GDM criteria. RESULTS:30 studies were eligible using 12 different sets of diagnostic criteria for GDM. Ten studies included n > 50, control group, assessment of GDM and BMI. Results were not uniform, but supported that higher BMI, higher age, Asian ethnicity, and fertility treatment increased the risk of GDM in PCOS. In OCC, women with PCOS and controls had similar prevalences of GDM independent of different sets of criteria for GDM. CONCLUSION:PCOS may not be an individual risk factor for GDM. Pregnancies in PCOS are characterized by factors known to increase risk of GDM, especially high BMI and fertility treatment.