Dr Alejandra Chaparro, the current Chair of the Chilean division of the International Association for Dental Research (IADR), is a dentist who specialises in periodontics at the University of Chile. 

Having obtained a master's degree from the Complutense University of Madrid in Dental Sciences specialising in Periodontics, Dr Chaparro works as a full professor and researcher at the Universidad de los Andes de Santiago de Chile. Her lines of research cover fields including periodontal medicine, oral biomarkers and oral regeneration. We talked with her about oral health and pregnancy. 

Is the association between periodontitis and adverse pregnancy outcomes still in dispute, or is this relationship now clear? 

Preclinical in vitro studies in animal models and clinical association studies in humans have demonstrated the biological plausibility of periodontal bacteria as colonisers of the fetoplacental unit, including the amniotic fluid and cavity, which until recently were thought to be sterile. In the fetoplacental unit, periodontal bacteria are capable of triggering an inflammatory immune response that causes the release of proinflammatory mediators similar to those involved in the pathogenesis of several adverse pregnancy outcomes. 

The controversy regarding this association basically exists because periodontal therapy fails to impact by reducing adverse pregnancy outcomes, and one of the reasons could be that most interventional studies have performed periodontal therapy during the second trimester of pregnancy, without being able to reduce adverse effects. 

Another difficulty in interpreting the studies is the lack of uniformity in the methodologies applied and the case definitions for both periodontal disease and adverse pregnancy outcomes. We need more scientific evidence to better understand the pathophysiology and risk profile of the association between periodontal disease and adverse pregnancy outcomes. We also need to determine the kind of treatment (type, the moment in or before pregnancy, intensity) and to identify the sub-populations of pregnant women who benefit most from these interventions. 

Can we consider the association between periodontitis and adverse pregnancy outcomes bidirectional? 

Undoubtedly. Pregnancy is itself considered a pro-inflammatory state, in which there are also hormonal variations that cause environmental changes and dysbiosis, affecting the relationship between bacteria and host in periodontal tissues, a situation that eventually results in greater gingival inflammation and bleeding. This inflammation and bleeding are used as nutrients by periodontal bacteria, which allows them to proliferate, probably evade host defence mechanisms, invade cells and enter the bloodstream to colonise distant organs such as the placenta. 

What are the latest developments in your research on periodontitis and adverse pregnancy outcomes? 

Our research group is currently centred on studying the association of periodontal pathologies with different adverse effects during pregnancy, and also on the analysis of potential placental and inflammatory biomarkers in oral fluids. When these are measured at the beginning of pregnancy, they allow for the prediction of the subsequent development of perinatal pathologies such as gestational diabetes, pre-eclampsia and pre-term delivery. We are studying and validating two biomarkers for the prediction of pre-eclampsia and gestational diabetes associated with clinical-maternal variables such as blood pressure and blood glucose in pregnant women. 

Will there be biomarkers for easy detection to prevent adverse pregnancy outcomes in the near future? 

The ultimate aim of our project is precisely to develop algorithms based on the determination of placental and inflammatory biomarkers in oral fluids combined with clinical-maternal variables that allow early prediction of perinatal pathologies in the least invasive manner possible, so that interventions can be performed to minimise the development of complications such as gestational diabetes, pre-eclampsia and pre-term delivery. 

Can you tell us about your studies on microvesicles? 

Extracellular vesicles are particles released by cells, and they were long believed to be responsible for eliminating cellular waste. However, recent studies have shown that they contain genetic material capable of remotely modifying cellular phenotypes, transforming cells to show an inflammatory or proliferative profile unlike that of the original. Our studies in this area are only beginning, and what we have observed is that in conditions of inflammation such as periodontitis or peri-implantitis, we can see more vesicles in the gingival crevicular fluid and that these contain different molecules such as microRNA and proinflammatory cytokines. We have likewise observed that some pregnant women who will develop gestational diabetes show increased extracellular vesicle counts in oral fluids from the beginning of pregnancy. 

The initial results of this line of research are exciting and very promising, but they must be validated, and we must fully research the role of these vesicles in the aetiopathogenesis of periodontal and peri-implant diseases. 

How can we raise a fertile woman’s awareness of the importance of oral care? 

Pregnant women should be provided with timely and appropriate education and warned of the importance of their oral health. Notwithstanding insufficient scientific evidence, perhaps the best alternative is to perform periodontal treatment prior to pregnancy and to provide education, prevention and periodontal maintenance visits in each trimester of pregnancy. For the time being and according to obstetric guidelines, it is recommended that procedures are to be avoided during the first trimester of pregnancy, with treatment preferably being delayed to the second trimester. 

What challenges does being Chair of the IADR Chile entail? 

As Chair of the IADR, together with the board, I have set the goal for this period of bringing research into clinical practice across all dental disciplines, moving the young to incorporate scientific methodology into their daily dental practice, as well as promoting the training of new young dental researchers. In addition, we want to advance in research to improve oral health and make Chilean research visible worldwide by facilitating communication and friendship ties between researchers and the formation of contact networks at national and international levels. 

WHAT RECOMMENDATIONS CAN WE OFFER FERTILE AND PREGNANT WOMEN? 

We must never tire of stressing the importance of prevention. If they are planning for pregnancy, they should schedule a check-up with their dentist to check their oral health in general and that of their gums in particular. They should not consider bleeding, reddened or swollen gums to be normal. 

Although more studies are needed to substantiate the association between periodontal disease and adverse pregnancy outcomes, the treatment of periodontitis does impact on the individual's systemic health by decreasing systemic inflammation, and this will also probably result in fewer complications during pregnancy, since at least gestational diabetes and pre-eclampsia are related to systemic inflammation. Ideally, treatment should be performed prior to pregnancy, with maintenance therapies in each trimester of pregnancy. Should gingivitis or periodontitis exist once pregnant, they should receive treatment in a timely manner and follow-up and maintenance controls throughout pregnancy, with proper control of the bacterial plaque by the patient at home.