Periodontal Disease and Diabetes Mellitus in Pregnancy: An Overview of Systematic Reviews.

Background: Periodontal disease has been increasingly associated with several systemic conditions, including diabetes mellitus. During pregnancy, both periodontitis and diabetes mellitus-including gestational and pre-existing forms (type 1 and type 2)-share common inflammatory and metabolic pathways that may influence maternal and neonatal outcomes. However, the consistency and strength of this association remain under debate. Objective: Our objective was to synthesize the available evidence from systematic reviews and meta-analyses on the association between maternal periodontal disease and diabetes mellitus during pregnancy, as well as its relationship with adverse pregnancy outcomes. Methods: An overview of systematic reviews was conducted following PRISMA recommendations. A comprehensive search was performed in PubMed, Scopus, Web of Science, and Cochrane CENTRAL from inception to the search date. A total of 161 records were identified, with 23 articles assessed in full text. Finally, nine systematic reviews were included, seven of which incorporated meta-analyses. Methodological quality was evaluated using AMSTAR 2, and risk of bias was assessed with ROBIS. Due to heterogeneity, a narrative synthesis was conducted. The degree of overlap among reviews was quantified using the corrected covered area (CCA). Results: The evidence consistently suggests a positive association between periodontal disease and diabetes mellitus during pregnancy, with increased risk reported in multiple meta-analyses, particularly for gestational diabetes mellitus. Periodontitis was also associated with adverse pregnancy outcomes, including preeclampsia, preterm birth, and low birth weight, although findings were not entirely homogeneous. The methodological quality of the included reviews was variable, predominantly low or critically low. A high level of overlap among reviews was observed (CCA = 15.2%). Conclusions: Current evidence supports an association between maternal periodontal disease, diabetes mellitus during pregnancy, and adverse maternal-fetal outcomes. However, these findings should be interpreted with caution due to methodological limitations and study overlap. Periodontal assessment in prenatal care and oral health education may be preventive strategies. Further studies are needed to clarify causality and evaluate these interventions.