Oxidant damage to DNA and pregnancy outcome

OBJECTIVE: DNA is susceptible to oxidation and is constantly being damaged and repaired in living cells. The most abundant of the nucleoside oxidation products is 8-oxo-7,8 dihydro-2 deoxyguanosine (8 OH-dG). Our objective was to determine whether oxidative damage to DNA, as measured by 8 OH-dG, is increased with poor pregnancy outcome. METHOD: We utilized a case-control design to study oxidative damage to DNA during an ongoing prospective study. Cases (n = 18) included all women giving birth to a low-birth-weight (< 2500 g) or growth-restricted (< 10th centile) or preterm infant (< 37 completed weeks). Controls (n = 34) were selected at random from women with normal pregnancies. Urine samples were obtained early in the third trimester (28 +/- 2 weeks) and normalized to creatinine. Diet was assessed at three points during pregnancy. RESULTS: Cases had significant (p < 0.05) increases in maternal urinary 8 OH-dG excretion at week 28, when all cases were considered and when cases were defined as those who delivered a low-birth-weight infant. 8OH-dG excretion, in turn, correlated positively with saturated fat in the maternal diet. CONCLUSION: This study suggests that gravidas with poor pregnancy outcome have increased oxidative damage to their DNA early in the third trimester of pregnancy.