Although associations between periodontal disease and adverse pregnancy outcomes have been shown, so far there is no evidence that periodontal treatment during pregnancy has a generally positive effect in reducing these outcomes.
That said, for certain types of pregnant women – those with other risk factors for adverse pregnancy outcomes, such as young or advanced age, smoking, previous pre-term births, low socio-economic status – periodontal therapy may have a beneficial effect on reducing these outcomes.
These are among the conclusions of the report The importance of Periodontal Disease Treatment during Pregnancy, written for the EFP/Oral-B Oral Health & Pregnancy project by Yiorgios Bobetsis and Phoebus Madianos.
“The main message is that non-surgical periodontal therapy during pregnancy, carried out mainly during the second trimester, is safe and generally effective in improving periodontal conditions,” says Phoebus Madianos, professor of periodontology in the School of Dentistry at the National and Kapodistrian University of Athens (Greece).
“However, it does not seem to reduce the risk of adverse pregnancy outcomes across populations – although a beneficial effect of periodontal therapy on pregnancy outcomes may be seen in certain patient subgroups.”
He suggests several reasons why non-surgical periodontal surgery during the second trimester of gestation might not consistently show an effect in reducing adverse pregnancy outcomes, such as low birth weight, pre-term birth, and pre-eclampsia.
First, absence of evidence is not evidence of absence. Or, as Prof Madianos puts it: “Although lack of causality between periodontal disease and adverse pregnancy outcomes is a possibility, we have to bear in mind that the lack of effect of an intervention does not translate into proof of non-causality.”
Instead, what it shows is that a specific intervention at a specific time was not able to modify the outcome.
The crucial factor here may be timing. It could be that providing periodontal treatment during the second trimester is too late to prevent or reverse adverse pregnancy outcomes.
“It is possible that, by the time of treatment, periodontal bacteria may have already reached the foetal-placental unit and may have contributed to the initiation of processes that lead to adverse pregnancy outcomes,” says Madianos, chair of the EFP’s scientific affairs committee.
He suggests that future studies should test earlier time points for periodontal intervention, including before conception, which “from a biological plausibility aspect may be more meaningful and potentially beneficial for the outcome of pregnancy.”
A second problem with the current state of the evidence is that in some of the existing studies periodontal intervention was not effective – treatment was not able to improve clinical periodontal parameters up to the accepted standard of care.
“It is apparent that future intervention studies should adopt stricter treatment end-points in order to determine whether periodontal treatment has an effect on pregnancy outcomes,” he explains.
Looking towards future research, he says that it would make sense “a main goal should be to identify and characterise patient subgroups – such as those with particular ethnic, microbiological, immunological characteristics, etc – that would benefit most from periodontal therapy in terms of pregnancy outcomes.”
He adds that this does not imply that only such women should receive periodontal treatment during or before gestation, as “improving periodontal conditions is a self-fulfilling goal for everyone, including all pregnant women.”
Turning to the guidelines that have been produced by the Oral Health and Pregnancy Project, Prof Madianos says that oral-health professionals should be aware of six key factors:
- The importance of preserving and establishing periodontal and dental health during pregnancy, and should inform and educate their patients accordingly.
- That non-surgical periodontal therapy and dental treatment, including restorations and extractions, are safe during pregnancy and especially during the second trimester of gestation.
- That dental x-rays can be taken when needed, with the appropriate protection, and local anaesthesia can be delivered without additional risk for the foetus or the pregnant woman.
- That the use of common painkillers and systemic antibiotics is generally safe, although tetracyclines should be avoided.
- That, as a general rule, medication should be prescribed to the pregnant woman after communication with her obstetrician.
- That all women should receive, at the start of pregnancy, a thorough evaluation of their dental and periodontal status. When gingivitis or periodontitis are diagnosed, periodontal treatment should be provided. Periodontal therapy will improve the periodontal condition and therefore the overall health of pregnant women.
Meanwhile, obstetricians are advised to be aware of the gum changes associated with pregnancy and that periodontal disease is associated with adverse pregnancy outcomes and that they should inform pregnant women accordingly.
They should also take initial steps to assess the presence of periodontal disease and refer pregnant women to dental professionals for proper diagnosis and treatment. In addition, obstetricians should inform women who are planning to conceive that it might be beneficial to the outcome of the future pregnancy to receive periodontal examination and treatment before becoming pregnant.
The advice to pregnant women is that they should be aware of the periodontal changes associated with pregnancy and that periodontal therapy during pregnancy is effective and safe both for them and for the foetus.
Pregnant women should visit a dental professional to receive a dental/periodontal examination and oral-hygiene instructions. Those with gingivitis or periodontitis should receive periodontal therapy during pregnancy to establish healthy periodontal conditions.
Women who are planning to become pregnant should visit a dental professional and, if necessary, receive periodontal treatment. These patients should be aware that “establishing periodontal health before conception and maintaining it throughout pregnancy may be beneficial for the future pregnancy outcome.”