Correlation Between Maternal-fetal Interface Inflammatory Changes And Placental Syncytial Knots In Promoting Spontaneous Preterm Birth

Significance:Preterm birth(PTB)refers to those who deliver from 28 weeks of pregnancy to less than 37 weeks of pregnancy.Preterm birth is the most important cause of neonatal death and a risk factor for postnatal growth and developmental disorders,especially neurodevelopmental disorders.The risk factors for premature birth,especially spontaneous preterm birth,and its specific mechanism are not fully understood.Traditionally,the cognition of maternal-fetal interface is sterile,but it is currently believed that premature delivery is a multifactorial pathological syndrome,which is related to infection,immunity and other factors.Spontaneous preterm delivery includes preterm birth and preterm delivery after premature rupture of membranes This article intends to explore the relationship between maternal-fetal interface inflammatory changes and syncytial knots in spontaneous preterm birth through pathological features and electron microscopy results of premature delivery after premature rupture of membranes,pretermbirth(without premature rupture of membranes)and full-term delivery of pregnant women,laying a theoretical foundation for a comprehensive understanding of the pathogenesis of premature delivery and interventional treatment of preterm delivery.Objective:1.Confirm that the inflammatory changes in the maternal-fetal interface are high-risk factors for spontaneous preterm delivery;2.Initially explore the correlation between syncytial knots and pretermbirth(without premature rupture of membranes);3.To evaluate whether leukocytes,neutrophils and C-reactive protein have predictive value for histological chorioamnionitis.Materials and methods:According to the inclusion and exclusion criteria,among the pregnant women who were hospitalized and delivered in Nanfang Hospital of Southern Medical University from January 2017 to December 2019,103 pregnant women with preterm birth afterpreterm premature rupture of membranes and 106 pregnant women of pretermbirth(without premature rupture of membranes)were selected,124 full-term pregnant women were used as a control group.Their general conditions(including height,pre-pregnancy weight,hospital admission weight and history of premature delivery,etc.),prenatal blood inflammation indicators(including white blood cell count,neutrophil count And C-reactive protein concentration)and other clinical data as well as the placental pathology after delivery and the electron microscopy results of part of the placenta.The above data were statistically analyzed using parameter test,Spearman correlation and Single factor regression analysis,was performed using SPSS 22.0 statistical software.P<0.05 was considered statistically significant.Results:1.The inflammatory changes in the placenta and membranes ofpremature rupture of fetal membranes is significantly worse than that of preterm birth(without premature rupture of membranes),most of them are severe chorioamnionitis.Preterm birth(without premature rupture of membranes)also has slight inflammatory changes in the placenta and membrane,which is not a sterile inflammation in traditional cognition.2.The incidence of syncytial knots inpreterm birthpreterm birth(without premature rupture of membranes)placenta is significantly higher than that of premature placental tissue with premature rupture of membranes.Under electron microscopy,there are multiple nuclei clustered at the syncytial knots,irregular morphology,uneven chromatin,and the cytoplasmic organelles are fully degraded,which is close to the change of syncytiotrophoblasts in the term placenta,suggesting syncytial knots and preterm birth(without premature rupture of membranes)closely related.3.Peripheral blood leukocyte count,neutrophil count,and C-reactive protein have weak predictive value for chorioamnionitis.The predictive value for severe chorioamnionitis is better than the overall predictive value of fetal membrane inflammation.Conclusions:1.Preterm birth(without premature rupture of membranes)has slight inflammatory changes in the placenta and membrane,which is not a sterile inflammation in traditional cognition,but that of it is significantly lighter than preterm birth afterpreterm premature rupture of membranes,and the difference has statistics meaning.2.The number of syncytial knots in preterm birth(without premature rupture of membranes)is significantly higher than that of preterm birth afterpreterm premature rupture of membranes,which tends to be full-term placental syncytiotrophoblast.Preterm birth(without premature rupture of membranes)placental trophoblast increase indicates that trophoblast function is reduced,and trophoblast senescence is related.3.Increased placental syncytial knots can play a synergistic role with inflammatory changes in the maternal-fetal interface and promote the occurrence of preterm birth(without premature rupture of membranes).4.Peripheral blood leukocyte count,neutrophil count,and C-reactive protein have weak predictive value for chorioamnionitis.Peripheral blood leukocyte count and neutrophil count is superior to general fetal membrane inflammation for severe chorioamnionitis.