Antenatal supplementation of antioxidant vitamins to reduce the oxidative stress at delivery--a pilot study

Abstract

Background: Preterm infants are at increased risk of oxidative stress and free-radical mediated diseases partly related to deficient antioxidant state. The purpose of this study was to investigate if maternal supplementation of antioxidant vitamins prior to delivery would reduce the oxidative stress in the mothers and their infants.

Study design: A pilot case-control study.

Patients and methods: Five mothers at risk of preterm delivery between 30 and 36 weeks were given a daily oral dose of betacarotene 20 mg, vitamin E 167.8 mg and vitamin C 1000 mg until delivery. Plasma levels of MDA and vitamins A, E and beta-carotene were measured prior to treatment in mothers and at delivery in both mothers and neonates. Seven mother-infant pairs comparable in gestation and birthweight acted as controls.

Results: In the supplemented group, median maternal plasma MDA at delivery was significantly lower compared to the pretreatment level (1.9 vs. 3.2 micromol/l, p=0.04) and it was also lower than the control group (1.9 vs. 3.65 micromol/l, p<0.001). In the supplemented group, median maternal plasma vitamin E at delivery was significantly higher than the levels prior to treatment (46 vs. 31 micromol/l, p=0.007) in the same group and those at delivery in the control group (46 vs. 30 micromol/l, p=0.03). There was a trend of lower plasma MDA and higher vitamin E at birth in infants born to supplemented mothers, but it did not reach statistical significance.

Conclusion: A short supplementation of multiple antioxidant vitamins to a small sample of preterm pregnant women reduced the oxidative stress at delivery in mothers and probably in their neonates. Larger studies probably using larger doses are needed to evaluate the efficacy of this strategy.