Background: We examined whether pregnant women with periodontal disease have an increased risk of preeclampsia, and we empirically evaluated the extent to which associations between periodontal disease and preeclampsia are dependent upon diagnostic criteria used to define periodontal disease operationally.
Methods: One hundred and fifty preeclampsia cases and one-fifty normotensive controls who delivered a singleton infant at term were enrolled. Periodontal examinations were performed within 48 h after delivery. Participants' periodontal health status was classified, a priori, into four categories according to the extent and severity of periodontal disease. Putative risk factors for periodontal disease and preeclampsia were ascertained during in-person postpartum interviews using a structured questionnaire and by medical record abstraction. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs).
Results: No clinically meaningful differences were observed between cases and controls with regard to periodontal parameters. After controlling for known confounders, severe clinical periodontal disease was not associated with an increased risk of preeclampsia (OR = 0.92, 95% CI: 0.26-3.28). In addition, there was no evidence of a linear increase in risk of preeclampsia with increasing severity of periodontal disease (P for trend = 0.65). When different diagnostic criteria previously used in other studies were used, the prevalence of periodontal disease varied substantially. However, the magnitude and direction of associations between periodontal disease and preeclampsia were largely similar regardless of the diagnostic criteria used to define periodontal disease.
Conclusions: This study provides no convincing evidence that periodontal disease is associated with preeclampsia risk among Thai women.