Objectives: Oxidative stress and inflammation are two key features of preeclampsia (PE). However, the impact of fetal sex and the mode of delivery on oxylipins still need to be characterized in the umbilical cord. Isoprostanoids like F2/3-isoprostanes (IsoPs), F4-neuroprostanes (NeuroPs) arise from the oxidation of arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) respectively. Prostanoids like prostacyclin and thromboxane were shown to be deregulated in PE. The docosanoids derived from DHA and EPA are involved in inflammation resolution and little is known about their levels in the umbilical cord. Goal: To assess the effect of preeclampsia (PE), mode of delivery and fetal sex on the levels of docosanoids and isoprostanoids in homogenates of the umbilical cord in normotensive and PE pregnancies. Methods: Normotensive (n=16 vaginal; n= 7 C-section; n= 8 male fetuses) and PE pregnancies (n=11 vaginal; n=7 C-section; n=10 male fetuses) were recruited. More than 50 oxylipins were profiled by LC-MS/MS. The data were analyzed by multivariate analysis and with generalized linear models adjusted for gestational age and mode of delivery. Results: The thromboxane, prostacyclin, the classical 15-F2t-isoP and resolvin D5 were all modulated by both PE and delivery mode (p<0.035). Four isoprostanoids including the 8-F2-IsoPs, 8-F3-IsoPs 4-F4-NeuroP were all affected by the three factors (delivery mode, sex and presence or not of PE; p<0.049). Conclusion: The umbilical cord levels of oxylipins can be affected by many cofounders such delivery mode and fetal sex besides PE. The effect of fetal sex on pro/anti-inflammatory and vasoactive mediators suggest that the umbilical is not isolated from the effect of the placenta, the mother and the fetus. This warrants further investigations.