Previous studies have explored the effect of periodontal treatment, irrespective of efficacy of treatment, in reducing infant prematurity. In a study titled "Risk of Preterm Birth Is Reduced with Successful Periodontal Treatment," lead researcher M. Jeffcott, and colleagues S. Parry and M. Sammel (all from the University of Pennsylvania, Philadelphia) and G. Macones (Washington University, St. Louis, Missouri) determined whether a reduction in infant prematurity was associated with successful periodontal treatment.
Pregnant subjects between 6 and 20 weeks gestation (using standard pregnancy dating criteria) were eligible for screening and enrollment. Eight hundred and seventy-two subjects with and without periodontal disease were followed. One hundred and sixty subjects with periodontal disease were treated with scaling and root planing. Subjects received periodontal examinations before and after scaling and root planing. Subjects were classified post-hoc according to the results of periodontal treatment: successful treatment ("non-exposure") or unsuccessful treatment ("exposure").
Groups were compared using standard bivariate statistics, odds ratios, and logistic regression analysis. Dichotomous outcomes were compared with chi-square where appropriate.
The primary study outcome for this clinical trial was the occurrence of spontaneous preterm birth <35 weeks. Subjects without periodontal disease had 7.2 percent rate of prematurity less than 35 weeks gestation; subjects with periodontal disease had 23.4 percent rate of prematurity <35 weeks gestation. Pregnant women who were refractory to scaling and root planing were significantly more likely to have preterm infants. Subjects who were successfully treated for their periodontal disease had a significantly lower incidence of preterm birth less than 35 weeks gestation.