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

doi:10.3877/cma.j.issn.1673-5250.2024.04.007

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）.

Results

①Among 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=11 562.700，95%CI：466.843-286 382.987，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 （χ²=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.

Key words: Uterine cervical incompetence, Pregnancy trimester，second, Cerclage，cervical，emergency, Pregnancy outcome, Nomograms, Pregnant women

表1 中孕期CI孕妇经阴道ECC后不良妊娠结局影响因素的单因素分析

组别	例数	年龄（岁， $\overset{ˉ}{x}$ ±s）	中孕期BMI（kg/m²， $\overset{ˉ}{x}$ ±s）	文化程度［例数（%）］		阴道炎史［例数（%）］	宫颈炎史［例数（%）］	流产史［例数（%）］
组别	例数	年龄（岁， $\overset{ˉ}{x}$ ±s）	中孕期BMI（kg/m²， $\overset{ˉ}{x}$ ±s）	初中及以下	高中及以上	阴道炎史［例数（%）］	宫颈炎史［例数（%）］	早孕期	中孕期
研究组	95	30.3±6.2	26.1±3.5	34（35.8）	61（64.2）	9（9.5）	11（11.6）	16（16.8）	72（77.4）
对照组	113	30.5±4.1	25.9±3.3	43（38.1）	70（61.9）	15（13.3）	21（18.6）	33（29.2）	45（39.8）
统计量		t=0.28	t=0.42	χ²=0.11		χ²=0.73	χ²=1.95	χ²=4.38	χ²=29.39
P值		0.781	0.672	0.736		0.393	0.163	0.036	＜0.001
组别	例数	宫颈手术史［例数（%）］	经产妇［例数（%）］	单胎妊娠［例数（%）］	术前生殖道感染史［例数（%）］	ECC时孕龄［例数（%）］		本次ECC中使用球囊辅助［例数（%）］	本次ECC中宫口扩张直径（cm， $\overset{ˉ}{x}$ ±s）
组别	例数	宫颈手术史［例数（%）］	经产妇［例数（%）］	单胎妊娠［例数（%）］	术前生殖道感染史［例数（%）］	＜24孕周	≥24孕周	本次ECC中使用球囊辅助［例数（%）］	本次ECC中宫口扩张直径（cm， $\overset{ˉ}{x}$ ±s）
研究组	95	38（40.0）	68（71.6）	81（85.3）	55（57.9）	65（68.4）	30（31.6）	35（36.8）	1.2±0.2
对照组	113	32（28.3）	36（31.9）	75（66.4）	62（54.9）	72（63.7）	41（36.3）	43（38.1）	1.0±0.1
统计量		χ²=3.15	χ²=32.57	χ²=9.82	χ²=0.19	χ²=0.51		χ²=0.03	t=6.99
P值		0.076	＜0.001	0.002	0.661	0.476		0.857	＜0.001
组别	例数	本次ECC中宫颈长度（cm， $\overset{ˉ}{x}$ ±s）	新生儿出生体重（g， $\overset{ˉ}{x}$ ±s）	分娩并发症［例数（%）］
组别	例数	本次ECC中宫颈长度（cm， $\overset{ˉ}{x}$ ±s）	新生儿出生体重（g， $\overset{ˉ}{x}$ ±s）	胎膜早破	前置胎盘	绒毛膜羊膜炎	产后出血	胎儿窘迫	宫颈裂伤
研究组	95	1.0±0.2	2 952.2±189.5	12（12.6）	1（1.1）	5（5.3）	2（2.1）	2（2.1）	2（2.1）
对照组	113	1.1±0.2	2 910.1±173.1	20（17.7）	3（2.7）	8（7.1）	4（3.5）	5（4.4）	6（5.3）
统计量		t=3.59	t=1.67	χ²=1.02	χ²=0.70	χ²=0.29	χ²=0.38	χ²=0.85	χ²=1.43
P值		＜0.001	0.096	0.313	0.627	0.590	0.690	0.458	0.295

表1 中孕期CI孕妇经阴道ECC后不良妊娠结局影响因素的单因素分析

组别	例数	年龄（岁， $\overset{ˉ}{x}$ ±s）	中孕期BMI（kg/m²， $\overset{ˉ}{x}$ ±s）	文化程度［例数（%）］		阴道炎史［例数（%）］	宫颈炎史［例数（%）］	流产史［例数（%）］
组别	例数	年龄（岁， $\overset{ˉ}{x}$ ±s）	中孕期BMI（kg/m²， $\overset{ˉ}{x}$ ±s）	初中及以下	高中及以上	阴道炎史［例数（%）］	宫颈炎史［例数（%）］	早孕期	中孕期
研究组	95	30.3±6.2	26.1±3.5	34（35.8）	61（64.2）	9（9.5）	11（11.6）	16（16.8）	72（77.4）
对照组	113	30.5±4.1	25.9±3.3	43（38.1）	70（61.9）	15（13.3）	21（18.6）	33（29.2）	45（39.8）
统计量		t=0.28	t=0.42	χ²=0.11		χ²=0.73	χ²=1.95	χ²=4.38	χ²=29.39
P值		0.781	0.672	0.736		0.393	0.163	0.036	＜0.001
组别	例数	宫颈手术史［例数（%）］	经产妇［例数（%）］	单胎妊娠［例数（%）］	术前生殖道感染史［例数（%）］	ECC时孕龄［例数（%）］		本次ECC中使用球囊辅助［例数（%）］	本次ECC中宫口扩张直径（cm， $\overset{ˉ}{x}$ ±s）
组别	例数	宫颈手术史［例数（%）］	经产妇［例数（%）］	单胎妊娠［例数（%）］	术前生殖道感染史［例数（%）］	＜24孕周	≥24孕周	本次ECC中使用球囊辅助［例数（%）］	本次ECC中宫口扩张直径（cm， $\overset{ˉ}{x}$ ±s）
研究组	95	38（40.0）	68（71.6）	81（85.3）	55（57.9）	65（68.4）	30（31.6）	35（36.8）	1.2±0.2
对照组	113	32（28.3）	36（31.9）	75（66.4）	62（54.9）	72（63.7）	41（36.3）	43（38.1）	1.0±0.1
统计量		χ²=3.15	χ²=32.57	χ²=9.82	χ²=0.19	χ²=0.51		χ²=0.03	t=6.99
P值		0.076	＜0.001	0.002	0.661	0.476		0.857	＜0.001
组别	例数	本次ECC中宫颈长度（cm， $\overset{ˉ}{x}$ ±s）	新生儿出生体重（g， $\overset{ˉ}{x}$ ±s）	分娩并发症［例数（%）］
组别	例数	本次ECC中宫颈长度（cm， $\overset{ˉ}{x}$ ±s）	新生儿出生体重（g， $\overset{ˉ}{x}$ ±s）	胎膜早破	前置胎盘	绒毛膜羊膜炎	产后出血	胎儿窘迫	宫颈裂伤
研究组	95	1.0±0.2	2 952.2±189.5	12（12.6）	1（1.1）	5（5.3）	2（2.1）	2（2.1）	2（2.1）
对照组	113	1.1±0.2	2 910.1±173.1	20（17.7）	3（2.7）	8（7.1）	4（3.5）	5（4.4）	6（5.3）
统计量		t=3.59	t=1.67	χ²=1.02	χ²=0.70	χ²=0.29	χ²=0.38	χ²=0.85	χ²=1.43
P值		＜0.001	0.096	0.313	0.627	0.590	0.690	0.458	0.295

表2 中孕期CI孕妇经阴道ECC后不良妊娠结局影响因素的多因素非条件logistic回归分析

影响因素	B	SE	Wald值	P值	OR值	OR值95%CI
既往早孕期流产史（vs无早孕期流产史）	-0.867	0.506	2.940	0.086	0.420	0.156～1.132
既往中孕期流产史（vs无中孕期流产史）	1.905	0.441	18.631	＜0.001	6.721	2.830～15.966
经产妇（vs初产妇）	2.240	0.471	22.633	＜0.001	9.397	3.734～23.652
单胎妊娠（vs双胎妊娠）	0.855	0.495	2.980	0.084	2.351	0.891～6.204
本次ECC中宫口扩张直径（连续变量）	9.356	1.638	32.640	＜0.001	11 562.700	466.843～286 382.987
本次ECC中宫颈长度（连续变量）	-3.182	1.203	7.002	0.008	0.042	0.004～0.438
常数项	-9.707	2.054	22.329	＜0.001	＜0.001	—

表2 中孕期CI孕妇经阴道ECC后不良妊娠结局影响因素的多因素非条件logistic回归分析

影响因素	B	SE	Wald值	P值	OR值	OR值95%CI
既往早孕期流产史（vs无早孕期流产史）	-0.867	0.506	2.940	0.086	0.420	0.156～1.132
既往中孕期流产史（vs无中孕期流产史）	1.905	0.441	18.631	＜0.001	6.721	2.830～15.966
经产妇（vs初产妇）	2.240	0.471	22.633	＜0.001	9.397	3.734～23.652
单胎妊娠（vs双胎妊娠）	0.855	0.495	2.980	0.084	2.351	0.891～6.204
本次ECC中宫口扩张直径（连续变量）	9.356	1.638	32.640	＜0.001	11 562.700	466.843～286 382.987
本次ECC中宫颈长度（连续变量）	-3.182	1.203	7.002	0.008	0.042	0.004～0.438
常数项	-9.707	2.054	22.329	＜0.001	＜0.001	—

图1 预测中孕期CI孕妇经阴道ECC后不良妊娠结局风险的列线图模型注：CI为宫颈功能不全，ECC为紧急宫颈环扎术

图2 预测中孕期CI孕妇经阴道ECC后不良妊娠结局列线图模型的校准曲线图注：CI为宫颈功能不全，ECC为紧急宫颈环扎术

图3 列线图模型预测中孕期CI孕妇经阴道ECC后发生不良妊娠结局的ROC曲线注：CI为宫颈功能不全，ECC 为紧急宫颈环扎术，ROC 曲线为受试者工作特征曲线

［1］	Bendet A，Leron E，Yarza S，et al.Cervical insufficiency a prologue for future pelvic organ prolapse？［J］.Arch Gynecol Obstet，2022，306（4）：1053-1061.DOI：10.1007/s00404-022-06555-8.
［2］	Gulersen M，Lenchner E，Nicolaides KH，et al.Cervical cerclage for short cervix at 24 to 26 weeks of gestation：systematic review and meta-analysis of randomized controlled trials using individual patient-level data［J］.Am J Obstet Gynecol MFM，2023，5（6）：100930.DOI：10.1016/j.ajogmf.2023.100930.
［3］	Hsieh MH，Chen CP，Sun FJ，et al.Changes in cervical elastography，cervical length and endocervical canal width after cerclage for cervical insufficiency：an observational ultrasound study［J］.BMC Pregnancy Childbirth，2023，23（1）：750.DOI：10.1186/s12884-023-06071-w.
［4］	Huang G，Deng C，Liao H，et al.Comparison of transvaginal cervical cerclage versus laparoscopic abdominal cervical cerclage in cervical insufficiency：a retrospective study from a single centre［J］.BMC Pregnancy Childbirth，2022，22（1）：773.DOI：10.1186/s12884-022-05108-w.
［5］	Giouleka S，Boureka E，Tsakiridis I，et al.Cervical cerclage：a comprehensive review of major guidelines［J］.Obstet Gynecol Surv，2023，78（9）：544-553.DOI：10.1097/OGX.0000000000001182.
［6］	Ikechebelu JI，Dim CC，Okpala BC，et al.Comparison of pregnancy outcomes of triangular 3-bites and mcdonald techniques of cervical cerclage in women with cervical insufficiency：a pilot study［J］.Niger J Clin Pract，2023，26（5）：630-635.DOI：10.4103/njcp.njcp_830_22.
［7］	中国妇幼保健协会宫内疾病防治专委会.子宫颈机能不全临床诊治中国专家共识（2023年版）［J］.中国实用妇科与产科杂志，2023，39（2）：175-179.DOI：10.19538/j.fk2023 020112.Intrauterine Disease Prevention and Control Committee of China Maternal and Child Health Association.Chinese expert consensus on the clinical diagnosis and treatment of cervical insufficiency（2023 edition）［J］.Chin J Pract Gynecol Obstet，2023，39（2）：175-179.DOI：10.19538/j.fk2023020112.
［8］	黎健，陈敏，刘乐山.基于R 软件的逐步Cox回归模型拟合及Nomogram 预测图绘制［J］.上海预防医学，2019，31（S1）：58-62.DOI：10.19428/j.cnki.sjpm.2019.19798.Li J，Chen M，Liu LS.Methodological application of stepwise Cox regression model fitting and predicting Nomogram construction based on R software［J］.Shanghai J Prev Med，2019，31（S1）：58-62.DOI：10.19428/j.cnki.sjpm.2019.19798.
［9］	Ocal A，Demirci O，Ozgokce C，et al.Protruding vs.visible prolapsed fetal membranes adversely a ffects the outcome of cervical insufficiency［J］.Eur Rev Med Pharmacol Sci，2023，27（20）：9937-9946.DOI：10.26355/eurrev_202310_34172.
［10］	Onishi K，Huang JC，Kawakita T.The effect of cervical cerclage on the labor curve［J］.Am J Obstet Gynecol MFM，2023，5（4）：100858.DOI：10.1016/j.ajogmf.2022.100858.
［11］	Meng L，Öberg S，Sandstrom A，et al.Identification of risk factors for incident cervical insufficiency in nulliparous and parous women：a population-based case-control study［J］.BMC Med，2022，20（1）：348.DOI：10.1186/s12916-022-02542-7.
［12］	闫慧慧，伍绍文，刘晓巍.孕中期经阴道紧急子宫颈环扎术治疗子宫颈机能不全影响妊娠结局的相关因素分析［J］.实用妇产科杂志，2022，38（7）：540-543.Yan HH，Wu SW，Liu XW.Analysis of the related factors affecting pregnancy outcome in the treatment of cervical incompetence by emergency cervical cerclage in second trimester［J］.J Pract Obstet Gynecol，2022，38（7）：540-543.
［13］	魏艳，罗剑儒，谢聪.不同术式治疗宫颈功能不全非孕期育龄女性与中孕期孕妇的临床疗效［J/OL］.中华妇幼临床医学杂志（电子版），2022，18（2）：158-164.DOI：10.3877/cma.j.issn.1673-5250.2022.02.006.Wei Y，Luo JR，Xie C.Effects of different surgical methods in the treatment of cervical incompetence in non-pregnant women of childbearing age and pregnant women in the second trimester［J/OL］.Chin J Obstet Gynecol Pediatr （Electron Ed），2022，18（2）：158-164.DOI：10.3877/cma.j.issn.1673-5250.2022.02.006.
［14］	Zeng C，Liu X，Zhao Y，et al.Pregnancy outcomes and factors affecting the clinical effects of emergency cerclage in twin pregnancies with cervical dilation and prolapsed membranes［J］.Int J Gynaecol Obstet，2022，157（2）：313-321.DOI：10.1002/ijgo.13774.
［15］	陈国庆，李晓东，周颖，等.子宫颈环扎术172例预后分析［J］.中国实用妇科与产科杂志，2023，39（2）：221-225.DOI：10.19538/j.fk2023020121.Chen GQ，Li XD，Zhou Y，et al.Analysis of prognosis of 172 patients with cervical cerclage［J］.Chin J Pract Gynecol Obstet，2023，39（2）：221-225.DOI：10.19538/j.fk20230 20121.
［16］	Lu Y，Zhu J，Yu X，et al.Perinatal outcomes of twin emergency cerclage：comparison with expectant treatment and singleton emergency cerclage［J］.J Obstet Gynaecol，2023，43（1）：2211658.DOI：10.1080/01443615.2023.22 11658.
［17］	YükselŞimşek S，Şimşek E，et al.Prevention of preterm delivery by cervical cerclage；a comparison of prophylactic and emergency procedures［J］.J Turk Ger Gynecol Assoc，2021，22（1）：22-28.DOI：10.4274/jtgga.galenos.2020.2019.0183.
［18］	Schneider K，Fimmers R，Jorgens M，et al.Emergency cerclage following a standardized protocol offers an effective and safe therapeutic option for women with high risk for prematurity-a retrospective monocentric cohort study on 130 pregnancies and 155 neonates［J］.J Matern Fetal Neonatal Med，2021，34（24）：4053-4059.DOI：10.1080/14767058.2019.1702960.
［19］	李泽丽，陈练，石慧峰，等.超声联合磁共振成像检查预测胎盘植入性疾病不良妊娠结局的列线图模型构建［J］.实用妇产科杂志，2023，39（4）：277-281.Li ZL，Chen L，Shi HF，et al.Construction of a nomogram model for predicting adverse pregnancy outcomes of placental implantable diseases by ultrasonography combined with magnetic resonance imaging［J］.J Pract Obstet Gynecol，2023，39（4）：277-281.
［20］	王蓓蓓，董启秀，郗红燕，等.早孕期孕妇药物流产失败的影响因素分析与构建相关预测模型及其对药物流产成功的预测价值［J/OL］.中华妇幼临床医学杂志（电子版），2023，19（5）：588-594.DOI：10.3877/cma.j.issn.1673-5250.2023.05.013.Wang BB，Dong QX，Xi HY，et al.Analysis of influencing factors of medical abortion failure of pregnant women in early pregnancy and construction of related prediction model and its predictive value for medical abortion success［J/OL］.Chin J Obstet Gynecol Pediatr （Electron Ed），2023，19（5）：588-594.DOI：10.3877/cma.j.issn.1673-5250.2023.05.013.

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