Psychoactive substance use and salivary periodontal pathogens among pregnant women in rural Rwanda.

Periodontal disease has been associated with adverse pregnancy outcomes, but evidence regarding the association between psychoactive substance use and periodontal pathogens during pregnancy remains limited, particularly in low-resource settings. This study examined the association between psychoactive substance use and salivary periodontal pathogen levels among pregnant women in rural Rwanda. This cross-sectional study was a secondary analysis of baseline data from a pregnancy cohort conducted in 2019 at a district hospital in Rwanda. A total of 178 pregnant women participated. Demographic characteristics, oral health behaviors, and psychoactive substance use were assessed using structured questionnaires. Salivary DNA copy numbers of four periodontal pathogens were quantified by quantitative real-time polymerase chain reaction, and associations were evaluated using multivariable generalized linear models. Women with a history of alcohol consumption before pregnancy had significantly higher levels of Tannerella forsythia than women who had never consumed alcohol (fold change 4.78, p = 0.006). Women with a history of drug use before pregnancy had significantly lower levels of Prevotella intermedia (fold change 0.29, p = 0.011), while women with a history of dental visits had significantly lower levels of Porphyromonas gingivalis (fold change 0.04, p = 0.014). These findings suggest that pre-pregnancy lifestyle factors and oral health behaviors are associated with the maternal oral microbial environment during pregnancy. However, because of the cross-sectional design, causal relationships and their potential implications for maternal and pregnancy outcomes could not be determined. Further longitudinal and mechanistic studies are warranted to clarify these associations and their potential clinical significance.