The Change of Oxidative Stress in Maternal Blood During Pregnancy

Oxidative stress (OS) is a state in which the oxidative capacity exceeds the antioxidant capacity in vivo. OS is associated with various perinatal diseases. There have been few reports about OS during pregnancy, such as OS changes that occur during gestation, normal maternal OS dynamics, and OS levels in umbilical cord blood. We here examined the oxidative and antioxidant capacity in maternal blood as well as in umbilical cord vein blood during normal pregnancy. Pregnant women managed from early pregnancy to the postpartum period in our hospital, from April 2018 to March 2019, were included. We obtained maternal blood at 12, 24, and 36 weeks of gestation and obtained umbilical cord blood at delivery. The OS (derivatives of reactive oxygen metabolites [d-ROMs]) and antioxidant capacity (biological antioxidant potential [BAP]) of blood samples were measured. D-ROMs and BAP were compared across gestational weeks. Moreover, d-ROMs and BAP were compared between mothers with and without disease. We analyzed 100 pregnancies (651 specimens). Eleven patients developed hypertensive disorder of pregnancy (HDP)/preeclampsia (PE). The median maternal age was 35 years, and the median gestational age at delivery was 39 weeks. Thirty-one women had undergone fertility treatments. D-ROM values were significantly higher and BAP values were significantly lower in mid- and late pregnancy than in early pregnancy. D-ROM and BAP showed no significant differences between HDP/PE and non-hypertensive groups. During pregnancy, maternal OS increases, and antioxidant capacity decreases with advancing gestational age.