IL6 and hydrops fetalis: Second, inflammatory activity has been negatively associated with cognition (Schram et al., 2007; van Oijen et al., 2005; Tampubolon, 2016), and inflammatory markers, including interleukin-6, white blood cell count, fibrinogen, and C-reactive protein, are inversely related to HF-HRV (Williams et al., 2019).