OBJECTIVETo evaluate the associations between periodontal conditions, serum level of interleukin-1beta (IL-1beta) and delivery outcomes in pregnant women with a diagnosis of threatened premature labor(TPL).

METHODSEighty systemically healthy pregnant women were enrolled in the study. The case group was composed of 40 pregnant women hospitalized with the diagnosis of TPL (TPL group) and the control group was composed of 40 normal pregnant women (Non-TPL group). Periodontal examinations included assessments of plaque index (PLI), clinical attachment loss (CAL), probing depth (PD), bleeding index (BI) and the percent of periodontitis sites (PD >3 mm, CAL > or =2 mm). The serum level of IL-1beta was determined using commercially available enzyme-linked immunoassays.

RESULTS(1) Fourteen of forty subjects of TPL group delivered premature labor infants (TPL-TB group), and twenty-six subjects delivered natural labor infants (TPL-PB group). No infants were delivered as premature labor infants in non-TPL group. There were significant differences in gestational age at delivery, birth weight, PLI, percentage of periodontitis sites and IL-1beta levels between the non-TPL group and TPL group or between the TPL-TB group and TPL-PB group (P < 0.05). (Significant negative correlation were observed between the gestational age at delivery and percentage of periodontitis sites as well as serum IL-1beta levels (P < 0.05). And significant positive correlation were observed between percentage of periodontitis site and serum IL-1beta levels (P < 0.05).

CONCLUSIONPeriodontal inflammation might be one of the pathogenesis of preterm birth.