Ubiquinol-10 and ubiquinone-10 levels in umbilical cord blood of healthy foetuses and the venous blood of their mothers

Despite their being good markers of oxidative stress for clinical use, little is known about ubiquinol-10 (reduced coenzyme Q(10)) and ubiquinone-10 (oxidized coenzyme Q(10)) levels in foetuses and their mothers. This study investigates oxidative stress in 10 healthy maternal venous, umbilical arterial and venous bloods after vaginal delivery by measuring ubiquinol-10 and ubiquinone-10 levels. Serum ubiquinol-10 and ubiquinone-10 levels were measured by HPLC with a highly sensitive electrochemical detector. Maternal venous ubiquinol-10 and ubiquinone-10 levels were significantly higher than umbilical arterial and venous levels (all p < 0.001). However, the ubiquinone-10/total coenzyme Q(10) (CoQ(10)) ratio, which reflects the redox status, was significantly higher in umbilical arterial and umbilical venous blood compared to maternal venous blood (all p < 0.001). The ubiquinone-10/total CoQ(10) ratio was higher in umbilical arterial than in umbilical venous blood (p < 0.01). The present study demonstrated that foetuses were under higher oxidative stress than their mothers.