Oxidant damage to DNA and pregnancy outcome

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.

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.

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.

This study suggests that gravidas with poor pregnancy outcome have increased oxidative damage to their DNA early in the third trimester of pregnancy.