The objective was to investigate the effect two modes of labor (vaginal delivery and elective cesarean section) on thiobarbituric reactive substances (TBARS) as markers of lipid peroxidation, total antioxidant power (ferric reducing ability, TAP), and total thiol molecules (TTM) in blood of mothers and their newborns. One hundred and twenty women with normal pregnancy and normal blood biochemical parameters were divided into groups of vaginal delivery (VD) and elective cesarean surgery (ECS). Blood samples were obtained firstly in the time 37-40 weeks of pregnancy and secondly during labor phase for VD or during ECS. Blood samples from umbilical cord arterial of newborns were also obtained at birth after separation of cord. Plasma levels of TBARS, TAP, and TTM were determined. There was no significant differences between VD and ECS mothers before labor in plasma levels of TBARS, TTM, and TAP. Mothers in the VD group showed a significant increase in TBARS (p < 0.05) after delivery. And TTM level showed a significant increase in ECS group (p < 0.05) as compared to pre-delivery levels. Comparing oxidative stress variables between VD and ECS groups after labor, plasma levels of TBARS, and TTM significantly increased (p < 0.05) in VD mothers. TAP was not significantly different between VD and ECS groups. Newborn of VD mothers showed a significant increase in TBARS (p < 0.05), and TAP (p < 0.05) as compared to newborn of ECS. TTM was not significantly different between two groups of newborns. The results indicate that mothers in VD and their newborns are in more oxidative stress than those who underwent ECS for delivery. Linking oxidative stress to severe neonatal diseases, it may be reasonable to assess whether antioxidant supplementation during pregnancy may reduce the frequency of neonatal diseases.