Maternal-neonatal 8-hydroxy-deoxyguanosine serum concentrations as an index of DNA oxidation in association with the mode of labour and delivery

Aim. To investigate the effect of the mode of labour and delivery on the total antioxidant status (TAS), and the biomarker of DNA oxidation, 8-hydroxy-deoxyguanosine (8-OHdG) serum levels, in mothers and their newborns. Subjects and methods. Some 106 women with normal pregnancy and normal blood biochemical parameters were divided into 4 groups: Group A ( n = 28) with normal labour and vaginal delivery ( VG), Group B ( n = 25) with scheduled cesarean section ( CS), Group C ( n = 26) with 'emergency' CS, and Group D ( n = 27) with prolonged labour + VG. Blood was obtained fr? m the mothers at the beginning of labour, and immediately after delivery ( pre- and post-delivery), as well as from the umbilical cord ( CB). TAS, 8-OHdG and creatine kinase (CK) were measured in the sera with appropriate methodology. Results. TAS levels were almost similar in all the groups pre- delivery, and in CB irrespective of the mode of labour and delivery, and remarkably decreased in Groups C and D post-delivery. 8-OHdG levels in Group C ( 0.94 +/- 0.08 ng/ml) and Group D (0.98 +/- 0.08 ng/ml) were significantly higher than those in Group A (0.26 +/- 0.01 ng/ml, p < 0.001) and Group B (0.28 +/- 0.07 ng/ml, p < 0.001) post-delivery. 8-OHdG levels were low in CB, independent of the mode of labour. CK positively correlated with 8-OHdG ( r = 0.48, p < 0.001), the latter negatively correlated with TAS ( r = - 0.53, p < 0.01). Conclusions. The lowest TAS and the highest 8-OHdG levels were found in Groups C and D post-delivery, probably due to the long-term participation of the mothers' skeletal and uterus muscles, whereas 8-OHdG levels were low in CB irrespective of the mode of delivery, possibly as a consequence of the antioxidant action of the placenta and/or the low lipid levels in the serum of the umbilical cord.