Clinical Analysis And Prediction Model Construction Of Cesarean Section Conversion For Full-term Primipara

Objective:To anayze the indications of cesarean section conversion in full-term primipara,compare the clinical data of the conversion to cesarean section,and build the prediction model of the conversion to cesarean section.Methods:A total of 6984 full-term,singleton,cephalic,and primipara women who were hospitalized in A Hospital from Juanuary 1,2017 to December 31,2021 and had the intention of vaginal trial delivery,and who had no contraindication to vaginal trial delievery after being evaluated by senior asset doctors were collected.According to the outcome of delivery,947 primiipara who transferred to cesarean section were divided into observation group,and 947 primmipara who had successful vaginal trial delivery were randomly selected according to the number of cases in the observation group,and the clinical data of the two groups.Through theχ~2test,single factor and multiple factor logistic analysis,finally screen out the independent influencing factors of conversion to cesarean section and establish the prediction model of conversion to cesarean section.Evaluate the prediction model by drawing the working characteristic curve of the subjects and the area under the curve,use R language to build the nomograph model,and use the self-expansion method tocarry out internal validation of the model.Results:1.From 2017 to 2021,The main indications for conversion to cesarean section were:fetal distress accounted for 23.9%,abnormal labor process accounted for 19.3%,relative cephalopelvic disproportion accounted for 17.1%,persistent occipital transverse and posterior position accounted for 16.5%,macrosomia accounted for 11.5%,followed by chorioamnionitis,placental abruption,umbilical cord abnormality,threatened uterine repture.2.Compared with the control group,there were significant differences in age,gestational age,BMI before pregnancy,delivery analgesia,conception mode,amniotic fluid,fetal weight and induced labor between the two groups(P<0.05),there was no significant difference in premature rupture of membranes and newborn sex between the two groups(P>0.05).3.After single-factor and multi-factor logistic regression analysis,age≥35 years old,gestational week≥41 weeks,pre-pregnancy BMI≥28,excessive weight gain during pregnancy,fetal body mass≥4000 g,abnormal fetal heart rate monitoring,and assisted reproductive conception were independent risk factors for conversion to cesarean section(OR>1,P<0.05),and the use of labor analgesia and induced labor were protective factors for conversion to cesarean section(OR<1,P<0.05).4.The prediction model of conversion to cesarean section was construted by combining independent influencing factors,and the area the curve was 0.743(95%CI:0.721～0.765).5.The consistency index of the results obstained from the internal validation of the nomogram model with the self-expension method is 0.743.Conclusion:1.From 2017 to 2021,fetal distress,abnormal labor process,relative cephalopelvic disproportion,persistent occipital transverse and posterior position,and macrosomia were the main indications for the transfer of full-term primipara to cesarean section due to vaginal trial failure.2.The age,gestational weeks,pre-pregnancy BMI,weight gain during pregnancy,fetal body mass,fetal heart rate monitoring results and pregnancy mode of full-term primipara are closely related to the conversion to cesarean section.The use of labor analgesia and induced labor are the protective factors for the conversion to cesarean section.3.The prediction model for conversion to cesarean section has a good discrimination and the accurancy,which can provide a reference for clinicians to choose appropriate delivery methods.