Effects of antioxidants and oxidative stress on pregnancy and infant growth: Korean perspectives

Pregnant women are susceptible to oxidative stress as a result of their weakened defense mechanism and comparative lack of antioxidants, which they sacrifice to the nutrient needs of the fetus. A Korean study has shown that pregnant women are much more likely than nonpregnant women to be deficient in vitamin B12. Maternal oxidative stress during pregnancy can have a profound and sustained impact on the development and growth of the fetus, newborn, and infant, as well as on the pregnant woman herself. Several studies carried out in Korea have reported that maternal deficiencies in antioxidants during midpregnancy or at the time of birth result in an adverse placental environment, decreased endothelial function, decreased apoptotic activity, and increased levels of oxidative stress. A significant relationship was found between increased placental levels of oxidative stress and birth size. Birth size parameters such as birth weight, head circumference-to-weight ratio, and ponderal index were lowest in the continuously high oxidative stress group. Furthermore, these adverse effects on fetal growth were found to have a long-term impact on subsequent postnatal infant and childhood growth. Infant weight and height at 6 and 12 months were adversely affected by maternal folate deficiency and increased oxidative stress during pregnancy. These effects on body weight and height persisted at 3 years of age. Conversely, high maternal vitamin C during pregnancy was associated with increased body weight and height both at birth and during childhood thereafter. These data suggest that the period of pregnancy not only is a critical window for the impact of oxidative stress on intrauterine and subsequent infant growth but also represents a period during which the intrauterine condition can be modified with regard to preserving levels of antioxidants. Therefore, applying interventions to pregnant women with high levels of oxidative stress at midterm could contribute to increasing birth size and infant growth.