The influence of maternal smoking habits before pregnancy and antioxidative supplementation during pregnancy on oxidative stress status in a non-complicated pregnancy.

Background: As a physiological condition closely linked with increased susceptibility to oxidative stress, pregnancy can be further compromised by cigarette smoking. Inadequate nutrition and reduced intake of antioxidants can also disrupt the prooxidant/antioxidant relationship and contribute to oxidative stress. Increased oxidative stress during pregnancy may be involved in several complications of pregnancy, such as preterm labor, fetal growth restriction, preeclampsia and miscarriage.

Objectives: The aim of this study was to investigate the influence of maternal smoking habits before pregnancy on the parameters of oxidative stress and the antioxidative defense system, lipid profile parameters and paraoxonase-1 (PON1) activity during the third trimester of uncomplicated pregnancies.

Material And Methods: Healthy pregnant women (n = 86) were divided into non-smoking and smoking groups, and into groups taking vitamin supplements and not taking them. Oxidative damage was measured through the levels of thiobarbituric acid-reacting substances (TBARS) and plasma antioxidant status was evaluated by measuring total antioxidant capacity (TAC).

Results: TBARS concetration was significantly higher (p < 0.05) and PON1 activity was significantly lower (p < 0.05) in the smokers' group. No significant differences were found in the investigated parameters in relation to vitamin supplement intake.

Conclusions: Habitual smoking before pregnancy is associated with increased oxidative stress. Vitamin supplementation has no effect on the oxidative stress status of healthy pregnant women.