Guerby Paul, Girard Mario, Marcoux Geneviève, Beaudoin Annie, Pasquier Jean-Charles, Bujold Emmanuel
Research Center, CHU de Québec-Université Laval, Québec, Canada.
Department of Obstetrics and Gynecology, Université de Sherbrooke, Faculté de Médecine et des Sciences de la Santé 3001, Sherbrooke, Quebec, Canada.
Am J Perinatol. 2023 Jan;40(2):187-193. doi: 10.1055/s-0041-1728818. Epub 2021 May 3.
The study aimed to estimate the predictive value of midtrimester cervical length (CL) and the optimal cut-off of CL that should be applied with asymptomatic nulliparous women for the prediction of spontaneous preterm birth (sPTB).
This is a prospective cohort study of asymptomatic nulliparous women with a singleton gestation. Participants underwent CL measurement by transvaginal ultrasound between 20 and 24 weeks of gestation. The participants and their health care providers remained blinded to the results of CL measurement. The primary outcomes were sPTB before 35 weeks and sPTB before 37 weeks. Receiver operating characteristics (ROC) curve analyses were performed. Analyses were repeated by using multiples of median (MoM) of CL adjusted for gestational age.
Of 796 participants, the mean midtrimester CL was 40 ± 6 mm with a 1st, 5th, and 10th percentile of 25, 29, and 32 mm, respectively. ROC curve analyses suggest that a cut-off of 30 mm was the optimal CL to predict sPTB before 35 weeks (area under the ROC curve [AUC]: 0.70, 95% confidence interval [CI]: 0.56-0.85) and before 37 weeks (AUC: 0.70, 95% CI: 0.59-0.80). Midtrimester CL <30 mm could detect 35% of all sPTB before 35 weeks at a false-positive rate of 5% (relative risk: 9.1, 95% CI: 3.5-23.5, < 0.001). We observed similar results using a cut-off of CL <0.75 MoM adjusted for gestational age.
A midtrimester CL cut-off of 30 mm (instead of 25 mm), or CL less than 0.75 MoM, should be used to identify nulliparous women at high risk of sPTB.
· The optimal CL cut-off for the prediction of sPTB is 30 mm in nulliparous women.. · In nulliparous women, a midtrimester CL < 30 mm is highly associated with sPTB before 35 and 37 weeks.. · A midtrimester of CL <30 mm (5th percentile) should define a short cervix in asymptomatic nulliparous women..
本研究旨在评估孕中期宫颈长度（CL）的预测价值以及应用于无症状未产妇预测自发性早产（sPTB）时CL的最佳截断值。
这是一项针对单胎妊娠无症状未产妇的前瞻性队列研究。参与者在妊娠20至24周期间接受经阴道超声测量CL。参与者及其医疗保健提供者对CL测量结果不知情。主要结局为35周前的sPTB和37周前的sPTB。进行了受试者操作特征（ROC）曲线分析。通过使用根据孕周调整的CL中位数倍数（MoM）重复分析。
796名参与者中，孕中期CL的平均值为40±6mm，第1、5和10百分位数分别为25、29和32mm。ROC曲线分析表明，30mm的截断值是预测35周前sPTB（ROC曲线下面积[AUC]：0.70，95%置信区间[CI]：0.56 - 0.85）和37周前sPTB（AUC：0.70，95%CI：0.59 - 0.80）的最佳CL。孕中期CL<30mm可在假阳性率为5%的情况下检测出35周前所有sPTB的35%（相对风险：9.以孕周调整的CL<0.75MoM作为截断值时，我们观察到了类似结果。
应使用30mm（而非25mm）的孕中期CL截断值，或CL小于0.75MoM来识别有sPTB高风险的未产妇。
·预测sPTB的最佳CL截断值在未产妇中为30mm。·在未产妇中，孕中期CL<30mm与35周和37周前的sPTB高度相关。·孕中期CL<30mm（第5百分位数）应定义为无症状未产妇的宫颈短。
