The influence of maternal cigarette smoking on placental pathology in pregnancies complicated by abruption

OBJECTIVE: The purpose of this study was to evaluate the effect of maternal cigarette smoking on placental histology in women with abruption. STUDY DESIGN: Data were derived from the New Jersey-Placental Abruption Study (NJ-PAS)-an ongoing, case-control study, conducted since August 2002 in 2 large hospitals in NJ. Abruption cases were identified based on a clinical diagnosis. Histologic evaluations were performed by 2 perinatal pathologists who were blinded to the abruption status. Maternal smoking during pregnancy was determined based on patient's self-report. Among abruption cases, histologic findings were compared between smokers and nonsmokers, and the association expressed as odds ratio ( OR) with 95% confidence interval (CI). All analyses were adjusted for potential confounders. RESULTS: A total of 189 abruption cases were available for analysis, of which 10.6% (n = 20) were smokers. Intervillous thrombus was more common in women who smoked (20%) than in nonsmokers (3.0%) (OR, 17.5; 95% CI, 3.1-99.4). However, placental infarcts were seen less frequently among smokers than nonsmokers (10.0% vs 32.5%; OR, 0.2; 95% CI, 0.1-0.8). CONCLUSION: These findings suggest that different pathologic mechanisms may be responsible for the histologic findings between smokers and nonsmokers diagnosed with placental abruption.