Effects of lifestyle factors on urinary oxidative stress and serum antioxidant markers in pregnant Japanese women: A cohort study

Oxidative stress plays a major pathological role in pregnancy-related complications. Although oxidative stress is induced by exogenous toxins in association with a poor lifestyle in normal subjects, there is little information on the factors altering oxidative stress and antioxidant levels during pregnancy. The purpose of this study was to determine the relationship between lifestyle factors and oxidative stress/antioxidant levels during each trimester and 1-month postpartum. This prospective cohort study followed 54 healthy women through pregnancy; first, second, and third trimester and 1-month postpartum. Participants were administered a questionnaire on characteristics and lifestyle factors. Morning blood and urine samples were obtained to measure urinary biopyrrins and serum coenzyme Q10 (CoQ10) levels. The levels of urinary biopyrrins and serum CoQ10 increased significantly throughout pregnancy, with peak values registered during the third trimester. Higher biopyrrin levels were significantly associated with non-consumption of morning meal during the first trimester, smoking during the third trimester and 1-month postpartum, alcohol consumption during the third trimester, high food-based polyunsaturated fatty acid intake during the third trimester, and poor mental health scores during the first and third trimesters. Higher CoQ10 levels were significantly associated with no smoking during pregnancy and at 1-month postpartum, and with a high frequency of exercise during the third trimester and 1-month postpartum. Thus, pregnancy represents a state of oxidative stress, which can be counterbalanced by increased levels of antioxidants, such as CoQ10. We speculate that certain lifestyle choices such as avoiding smoking can reduce oxidative stress and increase antioxidant levels during pregnancy.