Both spontaneous vaginal delivery and elective caesarean section influence neonatal redox status in dogs

Abstract

The influence of birth mode on redox balance is unknown in dogs. We aimed to compare antioxidant activity and oxidative stress of puppies born by elective c-section or vaginal delivery. Twenty-one bitches were elected for spontaneous vaginal delivery (n=10) and elective cesarean section (n=11) groups, considering only the first and last puppies born. Neonatal oxygen saturation, lactatemia, superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx) and total antioxidant capacity; marker of oxidative stress (thiobarbituric acid reactive substances [TBARS]) and protein oxidation were analysed at birth, 1h, 12h, 24h and 72 h. C-section newborns had lower oximetry at birth and 1h. Lactatemia was higher in the last vaginal delivery puppies and higher at birth, and 1h. Regardless of birth mode, last puppies had hyperlactatemia at birth. Vaginal delivery puppies had higher TBARS, while protein oxidation was higher in c-section, mostly in last puppies. C-section puppies had higher GPx activity, whereas GSH concentration decreased overtime. Surgically born puppies had lowering SOD between 12h and 72h. Vaginal delivery enhances lipid peroxidation, counteracted mostly by GPx. Conversely, c-section triggers protein oxidation, acutely scavenged by SOD and GSH, thus puppies are less exposed to the negative consequences of oxidative stress.