Cytokine Levels in Midtrimester Amniotic Fluid in Normal Pregnancy and in the Prediction of Pre‐eclampsia

Midtrimester amniotic fluid cytokines may reflect the function of the maternal immune system in the maternal-fetal interface and thus be predictive of pre-eclampsia. We determined the concentrations of interleukin (IL)-6, IL-8, IL-10, IL-11, IL-12, IL-15, tumour necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta in amniotic fluid at 14-16 weeks of gestation from women with normal pregnancies and from those who subsequently developed severe pre-eclampsia. The concentrations of the cytokines in amniotic fluid did not significantly differ between patients and normal controls. The median concentration of IL-6 was 950 pg/ml in normal pregnant women and 578 pg/ml in the patient group. The median concentration of IL-8 was 606 pg/ml in normal controls and 294 pg/ml in the patient group. The levels of IL-6, IL-8 and TGF-beta correlated positively with each other. TNF-alpha concentrations were low and similar in both groups. IL-10 and IL-12 were detected at very low levels in 37 and 7% of the samples, respectively. No difference was found in IL-15 concentrations between the groups. IL-11 was found only at low levels in both groups. Although none of the cytokines measured was predictive of pre-eclampsia, this study provides information of cytokines in amniotic fluid during the period when the spiral arteries are remodelled.