Maternal tobacco use is associated with increased markers of oxidative stress in the placenta

Objective: We sought to extend our prior observations and histopathologically characterize key metabolic enzymes (CYP1A1) with markers of oxidative damage in the placental sections from smokers. Study Design: Placental specimens were collected from term singleton deliveries from smokers (n = 10) and nonsmokers (n = 10) and subjected to a detailed histopathological examination. To quantify the extent of oxidative damage, masked score-graded (0-6) histopathology against 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxydeoxyguanisine (8-OHdG) was performed. Minimal significance (P <.05) was determined with a Fisher's exact and a 2-tailed Student t test as appropriate. Results: We observed a significant increase in the presence of syncytial knots in placentas from smokers (70% vs 10%, P =.02). These gross observations were accompanied by a significant aberrant placental aromatic hydrocarbon metabolism (increased CYP1A1, 4.4 vs 2.1, P =.002) in addition to evidence of oxidative damage (4-HNE 3.4 vs 1.1, P =.00005; 8-OHdG 4.9 vs 3.1, P =.0038). Conclusion: We observed a strong association between maternal tobacco use and aberrant placental metabolism, syncytial knot formation, and multiple markers of oxidative damage.