Analysis On Relevant Factors Of Previous Cesarean Scar Defect

[Objective]To investigate the mechanism and relevant risk factors accounting for the formation of previous cesarean scar defect(PCSD).[Methods]The parturients undergoing regular examination during pregnancy and caesarean section in Zhangjiagang Traditional Chinese Medicine Hospital from January 2017 to January 2019 were selected.Among them,48 parturients with PCSD occurring half a year after caesarean section were selected as subjects(research group),and 65 parturients without the occurrence of PCSD after caesarean section in the same period were selected as controls(control group).Observed indicators included:(1)general status of parturients:prenatal body mass index(BMI),age,gestational age at delivery and birth weight of newborns;(2)pregnancy complications and perioperative conditions:premature rupture of membranes,group B streptococcal infection during pregnancy,pregnancy with vaginitis,pregnancy complications,time of caesarean section,suture method for uterine incision in caesarean section,surgical duration,blood loss,postoperative leukocyte count and anemia;(3)the formation of the lower uterine segment recorded intraoperatively by surgeons;(4)uterine scarring:the interval between the last caesarean section,the frequency of caesarean section,and the healing of the scar at the lower uterine segment caused by the last caesarean section detected intraoperatively;(5)uterine ultrasonography after caesarean section:the location of the uterus,the size of the uterus six months after caesarean section,the state of the uterine cavity separation and the formation of PCSD.Based on the indicators above,the differences in the relevant factors of PCSD formation between the research group and the control group were analyzed.[Results]1.No statistically significant differences were found in general clinical baseline data including age,prenatal BMI,gestational age and neonatal weight between the research group and the control group(P>0.05),suggesting comparability.2.Compared with the control group,the proportions of group B streptococcal infection,pregnancy with vaginitis,premature rupture of membranes,pregnancy complications,abnormal increase in leucocytes after caesarean section,selective caesarean section and caesarean section when the uterine orifice opened more than 3 cm,poor formation of the lower uterine segment,single-layer suture of the lower uterine incision,retroverted uterine and separation of the uterine cavity as well as the frequency of caesarean section were significantly higher in the research group(P<0.05,OR>1,the lower limit of 95%confidence interval CI>1).Additionally,multivariate logistic regression analysis showed that group B streptococcal infection(P=0.049,OR=4.432,95%CI=1.003-19.578),premature rupture of membranes,abnormal increase in leucocytes after caesarean section,selective caesarean section and caesarean section when the uterine orifice opened more than 3 cm,frequency of caesarean section and retroverted uterine were finally included in the regression equation(P<0.05).That is to say,group B streptococcal infection,premature rupture of membranes,abnormal increase in leucocytes after caesarean section,selective caesarean section and caesarean section when the uterine orifice opened more than 3 cm,the frequency of caesarean section and retroverted uterine were all independent risk factors accounting for PCSD formation.3.Anemia,surgical duration and blood loss showed no statistically significant differences between the research group and the control group(P>0.05).4.In the research group,the proportions of poor healing of previous scar in the lower uterine segment,the interval between the last caesarean section<2 years,and the interval between the last caesarean section?5 years were significantly higher than those in the control group(P<0.05,OR>1,the lower limit of 95%CI>1).This suggests that the interval of 2-5 years between the second caesarean section and the last one can reduce the formation of PCSD.[Conclusions]1.Group B streptococcal infection during pregnancy is an important factor affecting PCSD formation.2.Multivariate regression analysis suggests that multiple factors are involved in PCSD formation,such as premature rupture of membranes,abnormal increase in leucocytes after caesarean section,selective caesarean section and caesarean section when the uterine orifice opened more than 3 cm,frequency of caesarean section and retroverted uterine.3.In second caesarean section,the risk of PCSD in parturients with an interval of 2-5 years between the last caesarean section is lower than that in those with an interval<2 years and ?5 years.4.PCSD formation is not related to age,prenatal BMI,gestational age,neonatal weight,anemia,surgical duration or blood loss separately or their combinations.