Circulating biochemical markers of inflammation, when elevated – even in the absence of clinical cardiovascular disease – have been shown to be associated with an increased risk of incident HF, persisting despite adjustment for ‘traditional’ cardiovascular risk factors: these include C-reactive protein (CRP) [3–14]; IL-6 [5,8,10,11,15]; TNF-α [8,10]; erythrocyte sedimentation ratio [16]; total blood white cell count [12]; blood granulocyte count [17]; growth differentiation factor-15 [18] and soluble ST2 (sST2) [18]. Here, IL6 is linked to hydrops fetalis.