A scientometric analysis of research related to the 'oral-placental axis' hypothesis: current status, hotspots, and future directions.

Oral diseases and placental disorders are closely associated with adverse pregnancy outcomes, and accumulating evidence supports their crosstalk that constitutes the "oral-placental axis". This study integrated scientometric and bioinformatic approaches to systematically analyze global research trends, collaboration networks, research hotspots, and core molecular-microbial mechanisms of the oral-placental axis covering the period from 2016 to 2025. A total of 196 eligible publications were retrieved from the Web of Science Core Collection, Scopus, and PubMed. Bibliometric visualization was performed using VOSviewer, CiteSpace, and R-bibliometrix, and bioinformatic analysis was conducted to identify shared genes, signaling pathways, and microbial links between oral and placental diseases. The results revealed an annual publication growth rate of 5.03%, with the United States, China, and Australia as major contributing countries, the University of Queensland as the leading institution, and Gomez-Arango Luisa F. and Nitert Marloes Dekker as the most influential authors. Core keywords included preterm birth, periodontal diseases, gestational diabetes mellitus, and oral microbiome, reflecting a research shift from phenotypic association to mechanistic exploration such as microbial vertical transmission and inflammatory signaling. Mechanistic analyses identified shared hub genes (e.g., KRT19, ADAMDEC1, AQP9, SPAG4, PLAT) and key pathways, predominantly primary immunodeficiency and complement and coagulation cascades. Pathogenic bacteria including Fusobacterium nucleatum and Porphyromonas gingivalis mediated adverse pregnancy outcomes via hematogenous spread and placental barrier disruption. This study established a bidirectional regulatory model of the oral-placental axis involving shared risks, microbial transmission, and systemic inflammation, providing a theoretical basis for preconception oral intervention and precise prevention during pregnancy, and supporting the integration of oral care into routine perinatal management.