Impact of chorioamnionitis on maternal and fetal levels of proinflammatory S100A12

Histologic chorioamnionitis (HCA) may lead to the fetal inflammatory response syndrome (FIRS). The aim of this pilot study was to evaluate S100A12, a marker of innate immune activation, in mothers with or without HCA and in their infants. Concentrations of S100A12, interleukin 6 (IL-6), and C-reactive protein (CRP) were evaluated in maternal, cord, and neonatal blood of very preterm infants. Histologic examinations of the placenta and umbilical cords were performed. The 48 mother-neonate pairs enrolled were subdivided into two groups: HCA group (N = 15) and control group without HCA (N = 33). Maternal S100A12 levels were similar between HCA and control group. Similarly, S100A12 concentrations in cord and neonatal blood did not differ between the groups. However, high S100A12 concentrations were detected in cord and neonatal blood of two out of three neonates exposed to HCA associated with advanced funisitis. Concentrations of IL-6 and CRP were higher in maternal blood of the HCA group compared with controls (p < 0.05, p < 0.001; respectively), but no differences in cord or neonatal blood was found. Conclusion:S100A12 did neither identify mothers with HCA nor very preterm infants exposed to HCA. It is currently unknown if S100A12 may identify neonates with FIRS.What is known:• Histologic chorioamnionitis (HCA) may lead to the fetal inflammatory response syndrome (FIRS).• S100A12 represents an early, sensitive, and specific diagnostic marker of inflammatory processes.What is new:• S100A12 did neither identify mothers with HCA nor very preterm infants exposed to HCA.• It is currently still unclear if S100A12 has a potential in identifying preterm infants with FIRS.