Associations Between Periodontal Status, Serum Cytokine Levels, And Delivery Outcomes In Pregnant Women With A Diagnosis Of Threatened Premature Labor

Preterm birth(PB) is the main cause of low birth weight(LBW) in pregnancy outcomes and major cause of perinatal morbidity and mortality.PB is related to a series of risk factors including age,race,smoking,alcohol,drug use,infections, preterm rupture of the membranes(PROM), chorioamnionitis, bacterial vaginitis , urinary infections, multiple pregnancy,and so on.25%without Traditional risk factors.Many investigators have accepted and fostered the view that prostagiandins,particularly PGF_2α and PGE₂ stimulates uterine tissues and the contractions that induce premature labor.Maternal serum levels of some cytokines have been reported to be associated with PB. Such cytokines include interleukin-6(IL-6),interleukin-l(IL-l), and tumor necrosis factor- α (TNF- α ) may stimulate the production ofprostagiandins in chorion, resulting in labor.Several scientists investigating the molecular basis of PB point to common cellular and biochemical pathways that seem to mediate the pathogenesis of PB, irrespective of the associated risk variables.PB that occurs as a result of infection is mediated indirectly, principally by the translocation of bacterial products such as endotoxin(lipopolysaccharide, LPS) and by the action of maternally produced inflammatory mediatora.Several studies have demonstrated an association between infection and PB.PB cases are 'probably caused by an infection of unknown origin.'Periodontal disease is a chronic inflammatory process mostly caused by infection by Gram-negative bacterium harboring next to the tooth surfaces.The lipopolysaccharide of such bacterium induces the production of cytokines by inflammatory cells. Periodontal infection which serve as reservoirs for Gram-negative anaerobic organisms,lipopolysaccharide(lPS, endotoxin),and inflammatory mediators including IL-1β and TNF- α , may pose a potential threat to the fetal-placental unit.lt has been reported that a significantly higher incidence of PLBW in gravid women with periodontal disease then without was reported.Periodontal and serologic examinations of women with threatened premature labor(TPL) may,therefore,provide detailed information for understanding the pathomechanisms of PB .However,no studies have been carried out to date in this specific group of pregnant women.The aim of the present study was to evaluate the associations of periodontal conditions with threatened premature labor and preterm birth in relation to serum cytokine leyels and the composition of subgingival plaque.Eighty women were enrolled in the study,during Jan.2003 and Dec. 2003.The case group was composed of 40 pregnant women hospitalized with the diagnosis of threatened premature labor(TPL). During the same period of time,the control group was composed of 40 normal pregnant women.All women in two groups were between 18 to 35 years old ,Gestational age between between 28³6weeks.All of them were Primiparae with singleten gestation and Educational level was above high school and had no history of Systemic conditions (severe anemia,diabetes,cardiovascular disorders,hepatic deficiency, venereal diseases,urinary infections),without hypertensive disorder complicating pregnancy,multiple pregnancy,placenta previa, PROM,chorioamnionitis, bacterialvaginitis.Periodontal examinations included assessments of plaque and gingivitis,clinicalattachment loss(CAL),probing depth(PD), bleeding index(BI) and plaque index (PI), before the oral examination, a peripheral blood sample was obtained from each subject with venipuncture using a vacuum tube. The sample was centrifuged at 2,500 rpm for 10 minutes, and the serum obtained was dissociated in a plastic tube. The tube was stored at -20℃ until analysis.The serum concentration of IL-1 β ,IL-6,TNF-was determined using commercially available enzyme-linked immunoassays(ELISA).Gestational age at delivery and the weight of the infants were recorded after each delivery.ResultsThere were no significant differences in the mean ages and Gstational age at examination between the non-TPL and TPL groups or between the TPL-TB,and TPL-PB groups...