The Association Between Periodontal Index As Well As Gingival Crevicular Fluid Biomarkers And Preterm Birth In Pregnancy

Background and objectionPreterm birth(PTB)which refers to delivery from 28 weeks to less than 37 weeks is the primary cause of neonatal death and morbidity.The rates of PTB are not decreasing obviously.There are many known risk factors for PTB,but there are still more than 50%of PTB that have not found any exact risk factors.For now,there is no predictor for PTB in asymptomatic women.Researchs suggested that periodontal diseases may be risk factors for PTB,and they may be related by a common inflammatory pathologenic mechanism.Periodontal pathogens might directly invade the fetal-placental unit through the blood circulation subsequently stimulating local inflammation;or inflammatory mediators are carried to the fetal-placental unit through the blood circulation,so that the inflammatory mediators reached the threshold in advance to trigger delivery.The project investigated the association between periodontal clinical index as well as biomarkers in gingival crevicular fluid(GCF)and PTB in different gestational stages,and explored the possibility of using the variables as predictors of PTB.MethodsNested case-control study was conducted.405 systematically healthy pregnant women within 36 weeks of gestation were selected,and grouped according to the enrolled week.Periodontal index,including probing depth(PD),bleeding index(BI),gingival index(GI)and five biomarkers in GCF,including IL-1β,IL-6,TNF-α,prostaglandin E2(PGE2)and 8-hydroxy-deoxyguanosine(8-OHdG)were measured by Enzyme-linked immunosorbent assay at the enrolled date.The detailed birth outcome was followed.Select preterm births as the study group,and according to the 1:4 ratio,select the full term births as the nested control group.Periodontal index and GCF biomarker levels between preterm birth and full-term birth in different groups were assessed.ResultsExcluding the number of lost follow-up and complications of pregnancy,300 pregnant women were enrolled finally,and 19 gave birth preterm(6.33%).According to the gestational week when the pregnant woman is enrolled,the pregnant women were divided into 9-12 weeks,13-23 weeks,24-28 weeks,and 29-36 weeks’ groups.The differences of GCF-IL-6 and GCF-8-OHdG levels between different pregnancy periods were statistically significant(P<0.05).Only women at 24 to 28 weeks of gestation,PTB displayed significant greater GI,BI and GCF-8-OHdG(P<0.05).With multiple logistic regression analysis,BI and GCF-8-OHdG are the dependent risk factors of PTB(OR=5.90,P=0.034;OR=1.18,P=0.045,respectively).Drawing receiver operating characteristic(ROC)curve,the area under the curve(AUC)of BI and GCF-8-OHdG were 0.80 and 0.69,that of the combined detection was 0.82,which is larger than individual detection,though the differences were not significant(P>0.05).The cut-off points of BI and GCF-8-OHdG alone were 1.68 and 35.01 pg/ml,while the combined detection were 1.86 and 33.87 pg/ml.The sensitivity,specificity and accuracy of BI and GCF-8-OHdG alone and combined detection according to the cut-off points were 85.7%,71.4%and 85.7%;71.4%,64.3%and 64.3%;77.1%,65.7%and 68.6%.ConclusionsIncreased BI and GCF-8-OHdG in 24-28 weeks of gestation are risk factors for PTB.The combined detection of the two has some value in the prediction of preterm birth,but further studies with a larger sample size are needed to explore it,thus,provide experiment evidence for establishing an early warning system for PTB in pregnant women with periodontal diesase.