Association between Porphyromonas gingivalis bacteria in infra-gingival plaque and premature labor with low birth weight

Context: There are some discrepancies regarding the association between periodontal disease and preterm in the literature. Considering all periodontal pathogens, Porphyromonas gingivalis (Pg) is the most invasive bacterium in connective tissues, and the impact of its presence in the diverse microbial community of periodontal pathogens with a lower frequency is much greater than expected. Aim: This study investigated the association of Pg in infra‑gingival plaque of preterm and low birth weight (PTLBW) mothers. Setting and Design: This descriptive correlational study was conducted on 89 women, who were referred to Imam Khomeini Hospital in Sari, Iran, in 2017. Materials and Methods: The samples were assigned by purposive method with 30 mothers had PTLBW newborns and 59 mothers had normal term and normal birth weight (NTNBW) neonates. The probing depth, bleeding on probing clinical attachment levels, plaque index, and gingival index were measured. A sample from the periodontal pocket was collected to distinguish the Pg in subgingival plaque by polymerase chain reaction. Statistical Analysis Used: The data were analyzed using descriptive statistics and the Mann–Whitney U and Chi‑square test. Results: According to the periodontal indexes, 37.3% and 26.7% of the mothers in the NTNBW and PTLBW were diagnosed with periodontitis, respectively. Furthermore, Pg was detected in 30% and 20.3% of the cases in the PTLBW of NTLBW mothers. The amount of Pg in infra‑gingival plaque was significantly higher in the PTLBW mothers than in the NTNBW (P = 0.016). Conclusion: The results indicated that the quantity of Pg could be considered a risk factor for PTLBW delivery.