Evidence grade associating periodontitis with preterm birth and/or low birth weight: II. A systematic review of randomized trials evaluating the effects of periodontal treatment

Aim: The aim of this systematic review was to evaluate whether maternal periodontal disease treatment (MPDT) can reduce the incidence of preterm birth (PB) and/or low birth weight (LBW). Methods: The Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were searched for entries up to October 2010 without restrictions regarding the language of publication. Only randomized-controlled clinical trials (RCTs) that evaluated the effect of MPDT on birth term and birth weight were included. The search was conducted by two independent reviewers and random-effects meta-analyses were conducted methodically. Results: Thirteen RCTs provided data, but only five trials were considered to be at a low risk of bias. The results of eight studies (61.5%) showed that MPDT may reduce the incidence of PB and/or LBW. However, the results of all meta-analyses showed contrasting results for PB [RR: 0.88 (95% CI: 0.72, 1.09)], LBW [RR: 0.78 (95% CI: 0.53, 1.17)] and PB/LBW [RR: 0.52 (95% CI: 0.08, 3.31)]. Conclusion: The results of this review show that MPDT did not decrease the risk of PB and/or LBW; however, the influence of specific aspects that were not investigated (disease diagnosis, extension and severity and the success of MPDT) should be evaluated by future RCTs.