Construction And Validation Of Prognostic Model For Premature Rupture Of The Membrane And Preterm Delivery After Conization

Objective:To investigate the prognostic factors of the premature rupture of the membrane(PROM)and preterm birth in pregnant women after cervical conization,we construct and preliminarily validate the prognostic model.Methods:84 women after conization in Women’s Hospital School of Medicine Zhejiang University were included in the retrospective study.The influence factors of PROM and preterm delivery were analyzed by Logistic regression analysis for getting a prognostic model respectively.A receiver operating characteristic(ROC)curve was established respectively.For analysis the predictive ability of the models.45 women who underwent conization were included to prove the prognostic model.The clinical value of PROM and preterm birth prognostic models for pregnant women after cervical conization were preliminarily validated.Results:Multivariate Logistic regression analysis found that cervical length(CL)(OR 0.3995%CI 0.19-0.84,p=0.015)during the second trimester was an independent predictor of PROM.The regression model wasLogit(P)=-0.315-0.934×CLThe areas under the ROC(AUC)was 0.72(95%CI 0.60-0.84).The sensitivity,specificity,Youden index,positive predictive value(PPV),negative predictive value(NPV)and accuracy with the cutoff value of 29.5mm were 68.5%,0.8%,0.393,47%,84%and 69%respectively.The AUC of the testing dataset was 0.92(95%CI 0.83-1.00).The sensitivity,specificity,Youden index,PPV,NPV were 85.7%,87.1%,0.728,75%,93.1%and 86.7%respectively.Mother’s age(OR 1.20 95%CI 1.01-1.43,p=0.037)and CL(OR 0.06 95%CI 0.01-0.21,p<0.001)during the second trimester were independent predictors of preterm delivery.The regression model wasLogit(P)=1.408-2.903×CL+0.186×ageThe AUC was 0.93(95%CI 0.87-0.99).The sensitivity,specificity,Youden index,PPV,NPV and accuracy with the cutoff value of-1.512 were 91.7%,81.5%,0.732,68.8%,95.7%and 84.5%respectively.The AUC of the testing dataset was 0.94(95%CI 0.86-1.00).The sensitivity,specificity,Youden index,PPV,NPV were 92.9%,90.3%,0.832,81.3%,96.5%and 91.1%respectively.Conclusion:CL is an independent predictor of PROM and preterm delivery in the second trimester of pregnancy after cervical conization,and the prognostic model can effectively predict the risk of PROM and preterm birth.For such women after cervical conization,especially for elder one,CL should be closely monitored during pregnancy in order to evaluate the clinical outcome and avoid the unnecessary clinical treatment.