ABSTRACT
<p><b>OBJECTIVE</b>To investigate the associations between periodontal diseases, presence of Porphyromonas gingivalis (P. gingivalis), serum levels of pro-inflammatory mediators and preterm low birth weight (PLBW).</p><p><b>METHODS</b>60 women (30 PLBW and 30 healthy women), were recruited after postpartum within 3 days in this case-control study. Periodontal measurements including plaque index (PI), bleeding index (BI), probing pocket depth (PD) and clinical attachment loss (CAL) were assessed. The subgingival plaque was collected before periodontal examination and analysed by polymerase chain reaction (PCR) for the presence of the 16S rRNA gene specific to P. gingivalis, while the venous and umbilical cord blood specimens collected were determined by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>The PLBW cases had a poorer oral conditions and the presence of P. gingivalis was found in a higher proportion in the PLBW than the healthy pregnant (56.7% vs. 30.0%, P < 0.05). Both of the presence of periodontitis and P. gingivalis have been found to be associated weakly with a shorter gestational age and a lower birth weight (P < 0.05). The levels of IL-1beta, IL-6 and prostaglandin-E2 (PGE2) in both of the blood samples showed higer levels between the PLBW and normal groups (P < 0.01). The IL-1beta and PGE2 levels in maternal serum were higher with a severe periodontal disease in the PLBW group (P < 0.01).</p><p><b>CONCLUSION</b>There may be a possible link between periodontal diseases and PLBW.</p>