Fetal plasma tumor necrosis factor concentration in normal pregnancy

The aim of the study was to investigate changes with gestation of fetal plasma tumor necrosis factor alpha (TNF-alpha) concentration. In a cross-sectional study, enzyme-linked immunoassay was used to measure plasma TNF-alpha concentration in 40 fetal blood samples obtained by cordocentesis (n = 25), cardiocentesis (n = 5) or at elective caesarean section (n = 10) at 12-38 weeks gestation. The fetal plasma concentration of TNF-alpha increased from a mean of 13.5 pg/ml at 12 weeks gestation to 37.5 pg/ml at 38 weeks (r = 0.59, p < 0.0001), and was significantly associated with the monocyte count (r = 0.56, p < 0.001). TNF-alpha is present in the fetal circulation from at least 12 weeks and the changes in plasma TNF-alpha concentration with gestation coincide with the development of the fetal monocyte-macrophage system.