Iron and Oxidative Stress in Pregnancy

Abstract

Pregnancy, mostly because of the mitochondria-rich placenta, is a condition that favors oxidative stress. Transitional metals, especially iron, which is particularly abundant in the placenta, are important in the production of free radicals. Protective mechanisms against free radical generation and damage increase throughout pregnancy and protect the fetus, which, however, is subjected to a degree of oxidative stress. Oxidative stress peaks by the second trimester of pregnancy, ending what appears to be a vulnerable period for fetal health and gestational progress. Conditions restricted to pregnancy, such as gestational hypertension, insulin resistance and diabetes, exhibit exaggerated indications of free radical damage. Antioxidants as well as avoidance of iron excess ameliorate maternal and early fetal damage. In rats both iron deficiency and excess result in free radical mitochondrial damage. Estimates of gestational iron requirements and of the proportion of iron absorbed from different iron supplemental doses suggest that with present supplementation schemes the intestinal mucosal cells are constantly exposed to unabsorbed iron excess and oxidative stress. Unpublished work carried out in Mexico City with nonanemic women at midpregnancy indicates that 60 mg/d of iron increases the risk of hemoconcentration, low birth weight and premature birth and produces a progressive decline in plasma copper. These risks are not observed in women supplemented with 120 mg iron once or twice per week. Studies on the influence of iron supplementation schemes on oxidative stress are needed.

Safety and benefits of antenatal oral iron supplementation in low‐income countries: a review

“…Most reports on this association concerned observational studies e.g. (Murphy et al , 1986; Zhou et al , 1998; Steer, 2000; Xiong et al , 2000; Casanueva & Viteri, 2003), which may be confounded because high haemoglobin concentrations may also be due to other pregnancy complications (e.g., a failure of the normal pregnancy‐induced physiological plasma volume expansion, pre‐eclampsia, hypertension) that can cause maternal and perinatal deaths.…”

Serum Ferritin in Gestational Diabetes

“…Iron overload can promote the generation of free radicals and result in deleterious cellular damages. Free radical-mediated tissue damage is generally accepted as a major mechanism underlying the occurrence of GDM [7,8,9] .…”

Oxidative stress status of highly prolific sows during gestation and lactation

“…It has been suggested that pregnancy is a state of oxidative stress, which is characterized by the placental production of reactive oxygen species including superoxide and hydrogen peroxide (Casanueva and Viteri, 2003;Myatt and Cui, 2004;Chen and Scholl, 2005). Excessive free radical production may cause both lipid and protein oxidation and impair normal endothelial cell function (Serdar et al, 2003).…”