Oxidative stress in term small for gestational age neonates born to undernourished mothers: a case control study

BACKGROUND The objective of this study was to assess the status of oxidative stress in term small for gestational age (SGA) newborn infants born to undernourished mothers by estimating levels of erythrocyte superoxide dismutase (SOD), catalase, reduced glutathione, and serum malondialdehyde (MDA) in cord blood and comparing them to healthy appropriate for gestational age (AGA) controls. This was done in a case control design at a tertiary level teaching hospital. METHODS We included 20 singleton healthy SGA newborn infants born between 38-40 weeks to undernourished mothers with a) post-pregnancy weight < 50 kg or height < 145 cm AND b) hemoglobin < 8.0 g/dL or serum albumin < 2.5 g/dL. An equal number of age and sex matched AGA newborn infants born to healthy mothers served as Controls. Mothers with other risk factors and newborns with complications during delivery or immediate newborn period were excluded. MDA, SOD, catalase and reduced glutathione were measured in the cord blood of all neonates and compared between the groups (unpaired t test); levels were also correlated to maternal weight, height, hemoglobin, and albumin by both univariate (pearsonian correlation) and multivariate (multiple regression) analysis. RESULTS The activity of MDA was increased (5.33 +/- 0.72 vs 2.55 +/- 0.22 nmol/mL; P < 0.0001) while levels of superoxide dismutase (493.6 +/- 54.9 vs. 786.8 +/- 79.1 U/g Hb; P < 0.0001), catalase (1.48 +/- 0.24 vs. 2.31 +/- 0.20 U/g Hb; P < 0.0001) and reduced glutathione (2.84 +/- 0.37 vs 6.42 +/- 0.23 Umol/g Hb, P < 0.0001) were decreased in term SGA born to undernourished mothers as compared to term AGA born to healthy mothers. On univariate analysis, all the markers of oxidative stress correlated significantly with maternal parameters (P < 0.005). On multivariate analysis, maternal albumin and hemoglobin accounted for maximum correlation with the markers of oxidative stress. CONCLUSIONS Intrauterine malnutrition is associated with significant oxidative stress in small for gestational age neonates born at term to malnourished mothers.