Increased Maternal Serum Interleukin-6 Concentrations at 11 to 14 Weeks of Gestation in Low Risk Pregnancies Complicated with Gestational Diabetes Mellitus: Development of a Prediction Model.

The aim of the study was to examine interleukin-6 (IL-6) maternal serum concentration at 11 to 14 gestational weeks in normal pregnancies and pregnancies complicated by gestational diabetes mellitus (GDM) and to create first trimester prediction models for GDM. Case-control study conducted in a Fetal Medicine Unit. Study population included 40 GDM cases and 94 controls. Maternal characteristics, first trimester ultrasound markers, biochemical indices, and IL-6 levels were used for our analysis. IL-6 was related to maternal weight among the maternal characteristics, (R(2)=0.0679, p=0.01). IL-6 was increased (p=0.001) in the GDM group (median=2 pg/ml) compared to the control group (median=1.5 pg/ml) even after adjustment for maternal weight. IL-6 was inversely related to birth weight adjusted for gestational age at delivery (r=-0.3382, p<0.001) and glucose levels at oral glucose test. Maternal weight and age were the only predictors of GDM among the maternal characteristics [Detection Rate (DR)=59.4%; for 25% False Positive Rate (FPR); Area Under the Curve (AUC)=0.7291; Model R(2)=0.1096, p<0.001]. IL-6 alone was a significant predictor of GDM (DR=51.3%; for 25% FPR; AUC=0.6731; Model R(2)=0.0616, p<0.001). Combination of maternal characteristics with IL-6 yielded an improved prediction (DR=67.5%; for 25% FPR; AUC=0.7586; Model R(2)=0.1521, p<0.001). IL-6 concentrations are increased at 11-14 weeks in pregnancies with GDM. Combination of maternal characteristics and maternal serum IL-6 levels may provide effective first trimester screening for GDM.