中孕期宫颈功能不全孕妇经阴道紧急宫颈环扎术后不良妊娠结局预测模型构建

Construction of a prediction model for adverse pregnancy outcomes after emergency cervical cerclage in pregnant women with cervical incompetence during the second trimester

目的探讨中孕期宫颈功能不全(CI)孕妇经阴道紧急宫颈环扎术(ECC)后不良妊娠结局影响因素,并构建和验证其不良妊娠结局风险预测模型。方法选择2017年3月至2023年4月南京鼓楼医院集团宿迁医院收治的采取经阴道ECC治疗的208例中孕期CI孕妇为研究对象。采用回顾性分析方法,根据CI孕妇妊娠结局,将其分别纳入研究组(n=95,分娩新生儿为早产、窒息、死产等不良结局者)与对照组(n=113,分娩正常新生儿者)。收集2组孕妇相关临床资料。采用成组t检验或χ^(2)检验,对中孕期CI孕妇经阴道ECC后发生不良妊娠结局的影响因素进行单因素分析与多因素非条件logistic回归分析。将多因素分析中筛选出来的影响因素,构建预测中孕期CI孕妇经阴道ECC后发生不良妊娠结局风险的列线图模型,并进行验证。本研究获得南京鼓楼医院集团宿迁医院医学伦理委员会批准(审批文号:2024040)。结果①本研究208例孕妇中,分娩新生儿窒息、早产、死产者分别为23、29、43例。②单因素分析结果显示,研究组孕妇既往中孕期流产史、经产妇、单胎妊娠占比及本次ECC中宫口扩张直径,均显著高于或长于对照组,而既往早孕期流产史占比、本次ECC中宫颈长度,则显著低于或短于对照组,并且差异均有统计学意义(P<0.05)。③多因素非条件logistic回归分析结果显示,既往中孕期流产史(OR=6.721,95%CI:2.830~15.966,P<0.001),经产妇(OR=9.397,95%CI:3.734~23.652,P<0.001),本次ECC中宫口扩张直径大(OR=11562.700,95%CI:466.843~286382.987,P<0.001),均为中孕期CI孕妇经阴道ECC后不良妊娠结局的独立危险因素,而本次ECC中宫颈长度长,则为其独立保护因素(OR=0.042,95%CI:0.004~0.438,P=0.008),根据这4项影响因素建立预测中孕期CI孕妇经阴道ECC后发生不良妊娠结局风险的列线图模型。④采用Bootstrap法内部验证该列线图模型的结果显示,C-指数为0.92(95%CI:0.86~0.97),具有良好区分度;校准曲线分析结果显示,理想曲线与校准曲线拟合度良好,Hosmer-Lemeshow检验结果显示,列线图模型预测的中孕期CI孕妇经阴道ECC后,不良妊娠结局风险与实际风险比较,差异无统计学意义(χ^(2)=0.24,P=0.624)。受试者工作特征曲线(ROC)分析结果显示,该列线图模型预测中孕期CI孕妇经阴道ECC后不良妊娠结局的敏感度为80.1%(95%CI:71.9%~87.3%),特异度为85.2%(95%CI:78.0%~92.1%),曲线下面积(AUC)为0.91(95%CI:0.87~0.95)。结论既往中孕期流产史、经产妇、本次ECC中宫口扩张直径及宫颈长度与中孕期CI孕妇经阴道ECC后不良妊娠结局风险有关。本研究构建列线图模型,有助于自中孕期CI孕妇中筛查经阴道ECC后不良妊娠结局高风险孕妇。

Objective To investigate the influencing factors of adverse pregnancy outcomes in pregnant women with cervical incompetence(CI)during the second trimester after emergency cervical cerclage(ECC),and establish and validate a risk prediction model for adverse pregnancy outcomes.Methods A total of 208 CI pregnant women during the second trimester who were treated with vaginal ECC in Nanjing Drum Tower Hospital Group Suqian Hospital from March 2017 to April 2023 were selected as study objects.According to the pregnancy o utcomes of CI pregnant women,they were included into study group(n=95,those with adverse pregnancy outcomes such as premature birth,neonatal asphyxia,and stillbirth)and control group(n=113,those with normal newborn deliveries)by retrospective method.The clinical data of pregnant women in two groups were collected retrospectively.Independent-samples t test or chi-square test was used to conduct univariate analysis of the influencing factors of adverse pregnancy outcomes in CI pregnant women during the second trimester after vaginal ECC,and multivariate unconditional logistic regression analysis was used to conduct multivariate analysis.The influencing factors screened out in multivariate analysis were used to construct a nomogram model for the risk of adverse pregnancy o utcomes in CI pregnant women during the second trimester after vaginal ECC,and to validate the model.This study has been approved by the Medical Ethics Committee of Nanjing Drum Tower Hospital Group Suqian Hospital(Approval No.2024040).Results①Among the 208 pregnant women,95 had adverse pregnancy outcomes,including 23 cases of neonatal asphyxia,29 cases of premature delivery and 43 cases of stillbirth.②Results of univariate analysis showed that the proportions of previous history of miscarriage during the second trimester,multipara and singleton pregnancy and the cervical dilation diameter in ECC were significantly higher or longer than those in control group,while the proportion of first trimester miscarriage history and cervical length in ECC were significantly lower or shorter than those in control group,and all the differences were statistically significant(P<0.05).③Results of multivariate logistic regression analysis showed that the previous history of miscarriage during the second trimester(OR=6.721,95%CI:2.830-15.966,P<0.001),multipara(OR=9.397,95%CI:3.734-23.652,P<0.001)and large cervical dilation diameter in ECC(OR=11562.700,95%CI:466.843-286382.987,P<0.001)were independent risk factors for adverse pregnancy outcomes after vaginal ECC in CI women during the second trimester,while large cervical length in ECC was its independent protective factor(OR=0.042,95%CI:0.004-0.438,P=0.008).And a nomogram prediction model for predicting the risk of adverse pregnancy outcomes in pregnant women with CI during the second trimester after vaginal ECC was established based on these four influencing factors.④Results of internal verification of the nomogram prediction model by Bootstrap method showed that C-index of the prediction model was 0.92(95%CI:0.86-0.97),which had good differentiation.Calibration curve analysis results showed that the ideal curve and calibration curve fit well.Hosmer-Lemeshow test results showed that there was no statistical significance between the risk of adverse pregnancy outcome predicted by the nomogram prediction model and the actual risk after vaginal ECC in CI pregnant women during the second trimester(χ^(2)=0.24,P=0.624).The results of receiver operating characteristic curve(ROC)analysis showed that the sensitivity and specificity of the model in predicting adverse pregnancy outcomes after vaginal ECC were 80.1%(95%CI:71.9%-87.3%)and 85.2%(95%CI:78.0%-92.1%),and the area under the curve(AUC)was 0.91(95%CI:0.87-0.95).Conclusions Previous history of miscarriage during the second trimester,multipara,cervical dilation diameter in ECC,and intraoperative cervical length in ECC are related to the risk of adverse pregnancy outcomes after vaginal ECC in CI pregnant women during the second trimester.The construction of a nomogram model in this study is helpful for early screening of CI pregnant women at high risk of adverse pregnancy outcomes after transvaginal ECC.