INTRODUCTION: Sphingolipids, essential to trophoblast and endothelial function, may impact inflammation in preeclampsia. However, their specific role in late-onset preeclampsia remains unclear. To address this research gap, we analyzed sphingolipid profiles in pregnancies at high risk for preeclampsia development to identify potential biomarkers and clarify their role in disease pathogenesis. MATERIALS AND METHODS: We monitored 90 pregnant women at high risk for preeclampsia development across four gestational points. These women were later categorized into the group of women with high risk who did not develop preeclampsia (HRG) (70 women) or the preeclampsia group (PG) (20 women). Sphingolipids (sphingosine, sphinganine, sphingosine-1-phosphate (S1P), ceramides C16:0/C24:0, and sphingomyelin C16:0) were quantified via liquid chromatography-tandem mass spectrometry. RESULTS: Sphingolipid profiles revealed distinct patterns between groups. Concentrations of S1P in the HRG increased from the 1st trimester to delivery (P <
0.001). We did not notice significant changes in S1P during pregnancy in the PG but compared with the HRG we found significantly lower concentrations at each test point from the 2nd trimester until delivery (P = 0.020, P = 0.013, P = 0.011, respectively). Ceramides C16:0 and C24:0 demonstrated significant increases over time in HRG (P <
0.001, both). Sphingomyelin C16:0 increased significantly across pregnancy in both groups (P <
0.001 in HRG and P = 0.006 in PG), with no significant differences between groups. CONCLUSIONS: We identified S1P as a potential biomarker for late-onset preeclampsia, with lower concentrations observed in PG compared to HRG. Rising sphingomyelin concentrations in both cohorts might serve as a relevant cardiovascular risk indicator in pregnancies at high risk for preeclampsia.