Objectives: The aim of the study was to determine maternal serum total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), paraoxonase (PON) and arylesterase levels in severe preeclamptic pregnants and also to investigate whether these parameters are implicated in the occurence of perinatal morbidity or not.

Material and methods: A case-control study was carried out including 60 pregnant women (30 with severe preeclampsia and 30 healthy controls). The optimal cut off points of oxidative stress markers for the diagnosis of severe preeclampsia and for the prediction of adverse perinatal outcomes were evaluated by receiver operating characteristic (ROC) analyses. Multi­variate logistic regression analysis was used to determine if a relationship between adverse perinatal outcomes and serum oxidative stress markers was present or not.

Results: TAS (OR = 37.486, 95% CI 3.535–397.519, p = 0.003), TOS (OR = 15.588, 95% CI 2.135–113.818, p = 0.007) and ary­lesterase (OR = 31.356, 95% CI 2.284–430.548, p = 0.01) were found to be diagnostic for preeclampsia. Statistically significant positive correlation of adverse perinatal outcomes with serum TAS, PON and arylesterase levels were determined. Besides, a significant negative correlation was found between serum TAS levels and gestational week (r = –0.342, p = 0.007) and also between serum PON levels and birthweight (r = –0.262, p = 0.043).

Conclusions: Increased maternal serum TAS, TOS and arylesterase levels are significantly associated with the presence of severe preeclampsia. Furthermore, elevated maternal serum TAS, PON and arylesterase levels are significantly and positively correlated with adverse perinatal outcomes. We suggest that in preeclampsia increased oxidative status may cause adverse perinatal outcomes and antioxidants may be increased in order to protect the fetus against oxidative damage.