Comparison of oxidative stress markers in umbilical cord blood after vaginal and cesarean delivery

OBJECTIVE The purpose of our study was to investigate the effect of the mode of delivery on the oxidant and antioxidant system in umbilical cord blood. METHODS We performed gas analysis of umbilical venous blood and umbilical arterial blood immediately after delivery in 38 women; eighteen women had a vaginal delivery while 20 women delivered via cesarean section at over 37 weeks gestation. We examined lipid peroxide concentration by thiobarbituric acid reaction, protein carbonyl content by 2,4-dinitrophenylhydrazine reaction, and total antioxidant capacity by oxygen radical absorbance capacity assay. RESULTS Lipid peroxide levels in umbilical venous blood were significantly higher in patients delivering by planned cesarean section (1.81 ± 0.06 nmol/mg protein) than those with vaginal delivery (1.24 ± 0.05 nmol/mg protein) (P < 0.05). Antioxidant capacity in umbilical venous blood was significantly higher in patients delivering by planned cesarean section (119.70 ± 0.13 µM/µL) than those with a vaginal delivery (118.70 ± 0.29 µM/µL) (P < 0.05). There was no significant difference in the carbonyl content of umbilical venous blood or in the lipid peroxide, carbonyl content, and total antioxidant capacity of umbilical arterial blood. CONCLUSION Lipid peroxidation levels and antioxidant capacity in umbilical venous blood were higher in patients delivering by planned cesarean section than those with a vaginal delivery. Therefore, we propose that both the mother and neonate are exposed to higher oxidative stress during cesarean section delivery.