IL6 and preeclampsia: Higher circulating IL-6 levels within both the mid and highest tertiles were observed more frequently in women with a history of early-onset preeclampsia compared to controls (P for trend <0.001), with an unadjusted OR of 3.4 for the mid tertile (95% CI 1.5 to 7.7) and 4.9 for the highest tertile (95% CI 2.2 to 11.0).