Salivary Prevalence of Four Oral Pathogens in Postpartum Women in Northeast Romania: An Exploratory Cross-Sectional Study

Background: Oral dysbiosis during pregnancy has been associated with adverse outcomes, including preterm birth, premature rupture of membranes (PROM), and low birth weight, yet oral health remains an underappreciated component of routine prenatal care. Dental caries and gingival bleeding are frequently reported during pregnancy and may remain clinically relevant in the immediate postpartum period, but their relationship with specific oral pathogens in postpartum women has been insufficiently characterised, particularly in Eastern European populations. Methods: This exploratory cross-sectional, single-centre study included 60 postpartum women recruited consecutively at “Cuza-Vodă” Clinical Hospital of Obstetrics and Gynecology, Iași, Romania, between December 2025 and February 2026. All participants completed a structured questionnaire covering obstetric history, demographic characteristics, and oral hygiene behaviours and underwent a standardised clinical oral examination by two calibrated examiners. Before study initiation, the two examiners underwent a joint calibration session based on the predefined visual oral assessment criteria used in this study and agreed on uniform recording procedures for visible dental caries, self-reported gingival bleeding during brushing, tooth mobility, and overall oral status. Saliva samples were collected after delivery. Genomic DNA was extracted using a magnetic-bead protocol and analysed by Real-Time PCR using TaqMan-based assays to detect four oral pathogens: Porphyromonas gingivalis, Streptococcus mutans, Mycoplasma salivarium, and Fusobacterium nucleatum. Results: Most participants were primiparous (55.0%) and delivered at term (≥37 weeks of gestation; 78.3%). The prevalence of pathogen detection was: P. gingivalis 38.3% (23/60), S. mutans 70.0% (42/60), M. salivarium 71.7% (43/60), and F. nucleatum 100% (60/60). Poly-microbial carriage was common: 15.0% of participants carried all three variable pathogens simultaneously (S. mutans, M. salivarium, and P. gingivalis), and the most frequent two-pathogen combination was S. mutans + M. salivarium (30.0%). No statistically significant associations were identified between pathogen detection and clinical or obstetric variables, consistent with limited statistical power in this small convenience sample. Conclusions: This exploratory study provides the first salivary prevalence estimates for these four oral pathogens in postpartum women in Northeast Romania. The high prevalence of poly-microbial carriage, including the novel quantitative estimate for M. salivarium, provides an empirical foundation for power calculations and future confirmatory research integrating standardised periodontal assessment with pregnancy outcome data.