Relevance of maternal sodium level for preeclampsia-associated adverse pregnancy outcomes

•A decreasing sodium level is associated to preeclampsia-related adverse pregnancy outcomes.•The sFlt-1/PlGF level and the sodium level have a negative linear correlation.•The sodium level is positively associated to the remaining pregnancy duration in patients with high risk for preeclampsia. To evaluate maternal sodium levels in women with preeclampsia (PE) or at high risk for preeclampsia and their relevance for severe PE-associated adverse pregnancy outcome and remaining pregnancy duration. In a retrospective cohort of 198 patients presenting with signs and symptoms of preeclampsia (PE), we investigated maternal sodium level and the sFlt-1/PlGF-ratio within 14 days prior to delivery. In total, 88 patients (44.4%) developed a maternal and/or fetal and neonatal preeclampsia-associated adverse outcome (AO). The median sodium level was lower in the cohort with vs. without AO (136 vs. 137 mmol/l) and correlated negatively with the sFlt-1/PlGF-ratio (r = −0.19, 95% CI: −0.31 to −0.05) in both groups. Logistic regression revealed a significant association of the maternal sodium level with the development of an AO (+1 mmol/l reduced the odds by 21%, [Odds ratio (OR) of 0.79 (95% CI 0.67–0.93), p