Treatment of periodontal disease in pregnancy

BMJ 2010; 341 doi: https://doi.org/10.1136/bmj.c7090 (Published 29 December 2010) Cite this as: BMJ 2010;341:c7090
  1. George Macones, professor and chair
  1. 1Department of Obstetrics and Gynecology, Washington University in St Louis, School of Medicine, St Louis, MO 63110, USA
  1. maconesg{at}wudosis.wustl.edu

Does not improve pregnancy outcomes, but should still be part of routine preventive care

Epidemiological studies have shown that clinical and subclinical periodontal infections during pregnancy are associated with preterm birth. Infection is thought to result in the release of proinflammatory cytokines, which have downstream effects on other biological pathways and tissues. The association was first noted for bacterial vaginosis in the 1980s and 1990s, and randomised controlled trials were then performed to assess whether screening and treating the infection during pregnancy would improve pregnancy outcomes. Most of these trials found no benefit, and such screening is not currently recommended.1 More recently, observational data have suggested that periodontal disease may also be linked to preterm birth and other adverse pregnancy outcomes.2 Several large clinical trials have since been performed to assess whether pregnancy outcomes can be improved with treatment.

In the linked systematic review (doi:10.1136/bmj.c7017), Polyzos and colleagues assess whether treatment of periodontal disease with scaling and root planing during pregnancy is associated with a reduced rate of preterm birth.3 The meta-analysis pooled the results of 11 randomised controlled trials, five of which were of high quality. Low quality studies tended to be much smaller than higher quality ones (with one study enrolling only 15 subjects per arm) and tended to overestimate the effect of treatment.4 Given the large number of participants (2303 active treatment, 2290 placebo treatment) and lack of heterogeneity in the high quality studies, they deserve greater emphasis. The pooled results of the high quality studies do not a support a reduction in the risk of preterm birth (odds ratio 1.15, 95% confidence interval 0.95 to 1.40), low birth weight (1.07, 0.85 to 1.36), spontaneous abortions or stillbirths (0.79, CI 0.51 to 1.22), or overall adverse pregnancy outcome (1.09, 0.91 to 1.30) with treatment with scaling and root planing. The implications of this study are clear—scaling and root planing for the treatment of periodontal disease in pregnancy cannot be recommended.

Many questions about periodontal disease and pregnancy outcomes still warrant further research, however. Firstly, how should periodontal disease be defined? Interestingly, no real consensus exists, and even among high quality studies the definition varies. However, treatment was not effective in any of the studies regardless of the definition used. Secondly, does completely eliminating periodontal disease during pregnancy (most studies do not look at how effective the treatment was) improve pregnancy outcomes? A recent secondary analysis of one high quality randomised clinical trial supports this notion, but further study is needed.5 Thirdly, would treatment at a different time—for example, before conception or very early in pregnancy—yield different results? Although an attractive theory, it may not be possible in everyday care because many women do not have interpregnancy care or even register for prenatal care early in pregnancy. Fourthly, would adjuvant treatment with antibiotics enhance the efficacy of scaling and root planing? So far, we have little evidence on adjuvant treatment during and outside of pregnancy. Fifthly, are specific oral bacterial pathogens often linked to preterm birth? Selective treatment of specific pathogens may be more effective. Lastly, is it possible, as shown in one randomised controlled trial, that treatment of periodontal disease can worsen some pregnancy outcomes?6 This phenomenon was also seen in a randomised trial of screening and treating asymptomatic trichomoniasis in pregnancy.7 Clearly, there are many avenues for future research on periodontal disease in pregnancy.

Disappointingly, despites years of basic, clinical, and translational research, no robust data support the treatment of any infection to reduce preterm birth or improve pregnancy outcomes. This includes bacterial vaginosis, periodontal disease, trichomoniasis, and sexually transmitted diseases. It may be time to re-examine some basic assumptions about the cause of adverse pregnancy outcomes and explore new mechanisms and treatments.

What should clinicians tell their patients about periodontal disease, oral health, and pregnancy? The maintenance of oral health is an important part of routine preventive care, and should be encouraged during and outside of pregnancy. But it should be done as part of routine preventive care, rather than specifically to improve pregnancy outcomes.


Cite this as: BMJ 2010;341:c7090


  • Research, doi:10.1136/bmj.c7017
  • Competing interests: All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

  • Provenance and peer review: Commissioned; not externally peer reviewed.


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