Methods: From Project Viva, an ongoing cohort study of pregnant women and their children, we included in this analysis participants who provided dental radiographs taken within 5 years before pregnancy and had blood collected during the first trimester (9.6 +/- 1.5 weeks¢ gestation), excluding smokers. We evaluated CRP levels among all 35 cases with periodontitis (i.e., at least 1 site with alveolar bone loss 3 mm or more) and a random sample of 67 controls matched on age and race/ethnicity. Plasma CRP was measured using high-sensitivity immunoturbidimetric assays. We performed linear regression analysis with log-transformed CRP levels as the outcome.
Results: The median CRP level was 2.23 mg/L (interquartile range, 0.74-4.14) in pregnant women with periodontitis and 1.48 mg/L (interquartile range, 0.71-3.70) in controls. After adjusting for age, race/ethnicity, education, income, pre-pregnancy body mass index, alcohol intake and gestational age at blood collection, mean CRP level was 68% higher (p=0.05) in women with periodontitis (2.52 mg/L, 95%CI 1.66-3.81) than controls (1.50 mg/L, 95%CI 1.12-2.00).
Conclusion: These results suggest that periodontitis increases plasma CRP levels in early pregnancy, and raise the possibility that CRP mediates the association of periodontitis with preterm birth.