No evidence that treatment of gum disease reduces the number of babies born before 37 weeks of pregnancy

Periodontal disease is a disease of the supporting tissues of the teeth that may affect the gums, periodontal ligament membrane, and bone around the tooth socket. It has been linked with infections, which some researchers believe could lead to or have an impact on a number of conditions, including problems in pregnancy. Periodontal disease is common in women of reproductive age, and gum conditions tend to worsen during pregnancy due to hormonal changes. The treatment involves bringing plaque on the teeth down to minimal levels, to reduce and resolve inflammation of the gums. It could involve counselling on oral hygiene measures, removing the plaque and calculus by using hand instruments (e.g. scale and polish) or ultrasound equipment (e.g. mechanical debridement), sometimes alongside the use of antibiotics or antiseptic mouthwashes or gels. If the nonsurgical treatment is not successful, surgery is sometimes required. This review assessed studies where pregnant women with gum disease were treated using a combination of techniques, with or without antibiotics.

What was the research?

A systematic review of the evidence to find out if treating gum disease can prevent adverse birth outcomes in pregnant women. Cochrane researchers collected and analysed all relevant randomized controlled trials to answer this question.

Who conducted the research?

The research was conducted by a team led by Zipporah Iheozor-Ejiofor from the University of Manchester, on behalf of Cochrane Oral Health. Philippa Middleton, Marco Esposito and Anne-Marie Glenny were also on the team.

What evidence was included in the review?

15 randomised controlled trials with 7,161 participants were included. Five trials were from North America, four from South America, three from Europe, two from Asia and one from Australia. Eleven studies compared either scaling and root planing or scale and polish with no treatment while the other four studies compared scaling and root planing with alternative mechanical treatments.

What did the evidence say?

When pregnant women with gum disease who receive periodontal treatment are compared with those who receive no treatment:

– there is no clear difference in the number of babies born before 37 weeks.
– there may be fewer babies born weighing less than 2500 g.

It is unclear if one periodontal treatment is better than alternative periodontal treatments in preventing adverse birth outcomes.

How good was the evidence?

The quality of the evidence was low.

What are the implications for dentists and the general public?

There is no evidence from randomized controlled trials that periodontal treatment prevents preterm birth. There is low-quality evidence that periodontal treatment may reduce low birth weight compared to no treatment.

What should researchers look at in the future?

The quality of the evidence was low, so further well-designed randomized controlled trials are needed. Future research should identify and target treatments at specific populations based on severity, ethnicity or socio-economic status. Treatment should be given in the first 12 weeks of pregnancy to increase the likelihood that it is successful. Studies should report on periodontal outcomes as well as pregnancy outcomes.


Iheozor-Ejiofor Z, Middleton P, Esposito M, Glenny AM. Treating periodontal disease for preventing adverse birth outcomes in pregnant women. Cochrane Database of Systematic Reviews 2017, Issue 6. Art. No.: CD005297. DOI: 10.1002/14651858.CD005297.pub3.

This post is an extended version of the review’s plain language summary, compiled by Anne Littlewood at Cochrane Oral Health’s Editorial Base.

1 thought on “No evidence that treatment of gum disease reduces the number of babies born before 37 weeks of pregnancy

  1. Pingback: Periodontal treatment during pregnancy-no evidence of impact on preterm birth - National Elf Service

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