The relationship between maternal oral health parameters, inflammatory blood markers, and the evaluation of their effects on preterm low birth weight | BMC Pregnancy and Childbirth

Currently, there is a lack of research examining the relationship between maternal oral and dental health, circulating inflammatory markers, and the incidence of preterm birth and low birth weight. The study’s conclusions are anticipated to contribute to a clearer understanding of the link between the systemic implications of oral and dental health and the etiopathogenesis of PLBW.

This study revealed statistically significant variations in oral health metrics (DMFT, DMFS, PI, GI, PD) and hematological markers (MPV/PLT, MPV, PCT, and leukocyte count) between the case and control cohorts. These differences, however, were deemed insignificant predictors of preterm birth and low birth weight (PLBW) in the regression analyses conducted.

Alternatively, the literature reveals an association between periodontal diseases and the incidence of preterm birth or low birth weight. Notably, a correlation has been observed between periodontitis and preterm birth, with some research suggesting up to a sixfold increase in risk [9]. Moreover, a deficiency in vitamin D, in conjunction with inadequate oral hygiene, has been documented as a contributing factor to preterm birth and low birth weight [11]. Notwithstanding, several studies refute this association, reporting no statistically significant relationship between periodontal diseases and preterm birth [10].

Unlike this study’s findings, other research has indicated no association between dental caries and preterm birth [5,6,7]. Nevertheless, a substantial correlation between tooth loss and premature birth has been highlighted in the literature [6]. The disparate findings across studies may result from methodological variations, specifically in the diagnosis of the disease, the criteria used to define preterm birth, and the measurement of infant weight. This study’s population comprised women who experienced preterm births and delivered infants with birth weights under 2.5 kg.

This study corroborates the established understanding that preterm birth is a multifaceted event resulting from the interaction of numerous factors, encompassing medical conditions (e.g., anemia, infertility, pre-existing diabetes), psychosocial and behavioral factors (e.g., depression, smoking, substance abuse), and pregnancy-related complications (e.g., premature rupture of membranes, multiple gestations, antepartum hemorrhage) [15,16,17]. The significance of oral health as a marker for periodontal disease is notable, given its potential to induce inflammatory responses impacting fetomaternal circulation and potentially leading to preterm birth [18]. The literature, however, suggests the insufficiency of a single biomarker or clinical parameter for predicting preterm birth owing to its multifactorial nature [18, 19]. A systematic review indicated that the pathophysiology of preterm birth is multifactorial, encompassing infection/inflammation and uteroplacental ischemia, thus necessitating a comprehensive risk factor assessment [18, 19]. Furthermore, preterm birth has been linked to maternal characteristics (sociodemographic, obstetric, and psychological) as well as paternal and environmental influences. Nevertheless, the study’s conclusions may be limited by the uncontrolled confounding effects of maternal lifestyle, maternal psychological conditions, and antepartum hemorrhage, impacting oral health and pregnancy outcomes [15, 20].

The study results emphasize the critical need to control for confounding factors in evaluating the relationship between maternal oral health and preterm birth. Interestingly, this study revealed a weak, positive correlation between periodontal indices (PI, GI, and PD—key indicators of periodontal inflammation and status) and leukocyte counts. The findings of this study support the understanding that periodontal bacteria and their associated by-products can breach tissue barriers and enter systemic circulation or have systemic effects [21, 22]. As an example, a study by Özdemir et al. [23] revealed significantly higher concentrations of DNI (immature neutrophil ratio), CRP (C-reactive protein), neutrophils, and leukocytes among patients diagnosed with periodontitis. Consistent with the foregoing, a meta-analysis established a link between periodontitis and changes in hematological markers, such as elevated leukocyte and neutrophil counts and higher erythrocyte sedimentation rates [24].

Severe periodontitis has been linked to systemic inflammation through the action of proinflammatory mediators, which stimulate hepatic responses and increase C-reactive protein levels [25]. Overall, the study’s results corroborate established processes and provide further evidence illuminating the relationship between systemic inflammation and periodontal health. Consequently, these results emphasize the crucial role of early identification and effective treatment of periodontal inflammation, especially within the context of pregnancy or pregnancy planning in women.

CBC results demonstrated statistically significantly higher levels of MPV/PLT, MPV, PCT, and leukocytes in the case group compared to the control group. The literature exhibits considerable heterogeneity for these parameters. For example, a reduction in MPV levels in individuals with preterm birth has been reported by Kurban et al. [26]. In contrast, Khatoon et al. reported no elevation in neutrophil counts amongst women experiencing preterm birth and no statistically significant variations in NLR, lymphocyte-to-monocyte ratio (LMR), or PLR [27]. Furthermore, a separate study revealed statistically significant variations in these biomarkers between preterm and term birth cohorts, most notably the neutrophil-to-lymphocyte ratio (NLR), hemoglobin (HGB), and platelet distribution width (PDW), indicating their potential utility in early preterm birth prediction [28]. Discrepancies might have resulted from study design variations, participant demographics, or methodological procedures. The variability in the blood parameters assessed and the discrepancies in the results obtained across studies indicate that these biomarkers may not explain the observed association completely.

The effective translation of these parameters into clinical practice necessitates further study. In addition, studies reveal a greater likelihood of serious illness in infants with low birth weight for gestational age, often necessitating advanced medical care, including neonatal intensive care, mechanical ventilation, and supplemental oxygen [29]. Correspondingly, thirteen preterm infants in this study required respiratory support and neonatal intensive care; the observed low Apgar scores in this group suggest a higher incidence of health complications, leading to greater resource consumption. Negative neonatal outcomes may result from inadequate maternal oral and dental health due to potential systemic inflammation, thereby highlighting the critical need for improved monitoring and management of maternal oral health throughout pregnancy.

This study’s significant contributions include its analysis of periodontal and dental health in PLBW and its utilization of the CBC test as a non-invasive and efficient method for assessing inflammatory markers, providing valuable insights into the pathogenesis of PLBW.

Among the study’s notable strengths is the comprehensive evaluation of maternal periodontal and dental health in the context of preterm low birth weight (PLBW). Implementing CBC tests in assessing inflammatory markers emerged as a significant advantage, as it proved an effective and non-invasive approach. Furthermore, the study’s exploration of the association between oral health and systemic inflammation and its potential contribution to the etiology of preterm birth has led to significant advancements in the field and has yielded valuable insights.

The study is not without its limitations. The bedside method of intraoral examinations is inherently limited in detecting minute variations in hard and soft tissue structures, as it relies on subjective clinical judgment, thus having reduced sensitivity compared to advanced diagnostic tools such as radiographic imaging or molecular analyses. The study’s restriction to a single center limited the generalizability of the findings, and it did not consider potential variations due to geographical, cultural, or socioeconomic factors. Furthermore, uncontrolled variables such as lifestyle factors, maternal nutrition, stress, and access to antenatal care might have influenced the observed associations. The cross-sectional design precluded the assessment of cause-and-effect relationships between oral health, systemic inflammation, and preterm birth. Finally, the absence of a comprehensive analysis of microbial factors, such as systemic inflammatory markers (e.g., cytokines) or specific periodontal pathogens, precluded a more nuanced understanding of mechanisms underlying the relationship between oral health and preterm birth.

Future studies should employ advanced diagnostic methods (e.g., radiographic imaging, molecular analyses) to enhance our understanding of the association between preterm birth and low birth weight and oral health. These studies should be conducted in multicenter settings, encompassing diverse populations, and should control for lifestyle factors such as maternal nutrition, stress, and prenatal care. Additionally, longitudinal prospective designs should further elucidate the relationship between preterm birth and low birth weight and oral health. In addition, a thorough examination of inflammatory markers (e.g., cytokines, CRP) and particular periodontal pathogens may facilitate a more comprehensive elucidation of the biological mechanisms underlying the association between preterm birth and low birth weight and oral health.