Periodontal Disease and Preterm Birth

Introduction:

The issue of ignored or non-treated periodontal disease (periodontitis) in pregnancy is a constant topic of research amongst periodontologists regarding its effects on preterm birth of the baby or even potentially low birth weight infants.

Pregnancy is indeed a dynamic phase of a woman's life characterized by many physiologic changes, but in regard to the periodontal disease of the oral cavity – evidence exists to confirm that these changes almost have a direct impact that increases the susceptibility factor to periodontal disease because of the hormonal increase in the females (progesterone and estrogen). The immune responsiveness, as well as inflammatory mediation, is definitely altered owing to the increased production of these hormones.

Host-derived inflammatory mediators are a major concern in pregnancy that follows the sequelae of gingivitis (untreated), leading to periodontitis that in turn is a risk factor for several systemic diseases, including cardiac disease, respiratory infections, and diabetes mellitus.

What Is Preterm Birth?

Preterm birth is when the infant is born before 37 weeks of gestation, and low birth weight is when the baby weighs less than 2500 g. Both are potential causative factors of morbidity, developmental disturbances, and mortality in neonates. Preterm birth and low birth weight in the medical literature are indicative of the mother's exposure to risk factors like low socioeconomic status, malnutrition, or systemic diseases.

Also, the public health challenge is to prevent preterm birth and low birth weight of newborn infants in developing and developed countries, both given that the infant's survival rates, morbidity, and mortality rates are also influenced by this criterion. Some studies though elusive and considered controversial, opinionate from traditional research methods that oral disease and bacterial accumulation are capable of causing upper genital tract infections that are in turn linked to the hypothesis of preterm birth and low birth weight due to periodontal destruction.

What Are the Biological Hypothesis and Link Between Periodontal Disease and Preterm Birth?

Periodontitis is usually caused by colonization by Gram-negative anaerobic bacteria in the subgingival areas. It thus acts as a distant reservoir that influences pregnancy and, in turn, contributes to the induction of preterm birth. Because mainly, these bacteria produce these inflammatory mediators like interleukin 1 beta, interleukin 6 (IL-6), prostaglandin E2, and tumor necrosis factor-alpha.

The main hypothesis is that bacterial pathogens have the ability to elude the host defense mechanisms and release the byproducts that affect the amniotic fluid and fetal circulation by reaching through the placental barrier. Porphyromonas gingivalis (P. gingivalis) is the most common bacterium as per case reports detected in human placenta tissues and also Fusobacterium nucleatum subspecies. Polymorphum strain, though not detected in vaginal samples of pregnant women who had preterm birth issues, was still found in gastric aspirates of neonates and the oral samples of these affected mothers with localized periodontitis. Polymorphisms in certain cytokines and certain pro-inflammatory genes are also possible because of bacterial colonization in the oral cavity that would increase the risk factor for preterm birth.

The dissemination of periodontal pathogens is rapid towards the fetal tissues according to some hypotheses causing immune reactions, especially pro-inflammatory mediators that are directly sampled in preterm weight infants after birth. Research shows particularly that IL-6 elevation in the second trimester in the amniotic fluid of the mother coincided with the initiation of preterm birth. This leads to the controversial and elusive but definitive link that establishes the direct impact of periodontal disease on the premature delivery of the child.

Hence the systemic changes that lead to exacerbation due to chronic or untreated periodontal disease or periodontitis can cause local inflammation inside the fetus by crossing the placenta, thus impacting and increasing the risk of preterm birth proportionally. Several systematic reviews and randomized control studies carried out in pregnant women over the last decade particularly emphasize that the research is controversial for periodontitis causing preterm birth, not because of lack of direct proof but due to the reason that only certain pregnant women who are at an increased risk or would be suffering from pre-eclampsia, HIV (human immunodeficiency virus) infected individuals, obese individuals prior to pregnancy and in certain susceptible genotypes transmitting the risk of maternal infections to the infant.

How Can Your Dentist Help Manage Preterm Birth and Low Birth Weight?

1. Dental procedures like routine scaling and prophylaxis to prevent the spread and control of periodontal pathogens are considered safe during the second trimester of pregnancy. However, research stresses that preconception dental and oral health would be crucial timing for preventing the pro-inflammatory mediators from crossing the fetoplacental unit.

2. Complete oral prophylaxis and dental restorative modalities prior to conception would indeed be more beneficial than getting the dental treatment in the second trimester. In the third trimester, it would prove particularly difficult for the patient to be seated or undergo routine dental procedures and, hence, not advised by physicians and surgeons.

3. Non-surgical periodontal therapies that comprise restorative, prophylactic, and even surgical treatment like tooth extractions are generally considered safe without posing any risk to the fetus, according to dentists generally in the second trimester of gestation.

4. Dental X-ray exposure should be limited, and unless absolutely indicated for the patient, it should be avoided.

5. Tetracycline usage is strictly contraindicated in pregnancy, though general antibiotics and painkillers for relieving dental pain like Amoxicillin 500 mg (or 625 mg) are considered quite safe to use in pregnancy.

6. Thorough periodontal and dental evaluation at the start of pregnancy can help the dentist plan the treatment in phases and timings accordingly to prevent the risk of dental infections leading to systemic infections.

7. Obstetricians should also spread awareness on the importance of oral hygiene and the potential risks of low birth weight and premature birth adverse effects that would be caused in high-risk patients [pregnancy with systemic diseases, HIV infection, UTIs (urinary tract infections), pre-eclampsia, etc.].

Conclusion:

Though further research is underway, the established prospect of oral, especially periodontal health and its impact on premature birth and low birth weight infants is a possibility not to be ignored. Adequate oral hygiene measures, timely dental treatment, and prevention of systemic diseases in pregnancy can be life-saving and positively impactful both to the mother and the child.