Mathematical Modeling of Obstetric Variables: Influence of COVID-19, Periodontal Disease and Dental Care During Pregnancy

<b>Background:</b> Systemic inflammatory factors may be altered by periodontitis and/or COVID-19, potentially increasing the risk of adverse pregnancy outcomes, a relationship that remains unclear. <b>Objective:</b> This study aimed to identify associations between periodontitis and COVID-19 during pregnancy, evaluating the influence of dental care on obstetric variables through set theory and probability. <b>Methods:</b> A quantitative, cross-sectional, and correlational study was conducted in two phases. The first phase analyzed 156 medical records from 5 institutions, including gynecological and periodontal data; the second phase examined 104 records from a single institution selected for data completeness (2020-2021). Descriptive statistics, bivariate analysis, chi-square tests, and odds ratios were applied. Set operations (union, intersection) and relative probabilities were calculated using R and Excel. Sets represented dental care, dental disease, COVID-19 diagnosis, gestational age, neonatal weight, and complications. <b>Results:</b> In Phase 1, 37% of pregnant women were COVID-19-positive, 44% vaccinated, 51.9% underwent cesarean section, and 5.12% had periodontitis. In Phase 2, 76 pregnant women did not receive dental care, while 28 did; among them, 6 were COVID-19-positive. Mean neonatal weight ranged from 2336 g (dental care) to 2271 g (no dental care). COVID-19-positive pregnant women showed fewer complications and a higher proportion of normal-weight neonates. Gingivitis was the most frequent periodontal condition (75%). No statistically significant differences were observed between the analyzed sets. Conclusions: no direct relationship was found between periodontitis and neonatal weight in COVID-19-positive cases. Dental care did not influence maternal-fetal outcomes. The methodology provides an innovative framework for clinical analysis through mathematical abstraction.