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

ABSTRACT

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 from 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.