Oxidative stress varies with the mode of delivery in intrauterine growth retardation: association with Apgar score.

OBJECTIVE: To assess if oxidative injury in intrauterine growth retarded and healthy newborns is affected by the mode of delivery and whether Apgar score as a marker of neonatal survival is dependent on lipid and protein oxidative injury assessed by measuring malondialdehyde and protein carbonylation. METHODS: 30 IUGR newborns, 15 born by normal vaginal delivery and 15 born by elective caesarean section, and 40 healthy control infants, 30 born by normal vaginal delivery and 10 born by elective caesarean section, were studied at birth. Cord blood was collected for determination of malondialdehyde and protein carbonylation. RESULTS: IUGR newborns had significantly elevated MDA and protein carbonylation than the control group. Apgar scores, both at 1 and 5 min, were significantly lower in the IUGR group. These were assessed by independent sample t test. Using one-way ANOVA we found that MDA and protein carbonyls levels were not statistically different in healthy control group and in IUGR subgroup born by caesarean section however they were significantly different in other groups. Linear regression analysis revealed that Apgar scores both at 1 min and 5 min were dependent on MDA in IUGR newborns. Apgar score was however not dependent on protein carbonylation in the same group. CONCLUSION: Apgar score in IUGR newborns is dependent on the extent of oxidative injury and elective caesarean section minimises the same.