Mid-trimester endovaginal sonography in women at high risk for spontaneous preterm birth
Mid-trimester endovaginal sonography in women at high risk for spontaneous preterm birth
复制标题
DOI：
10.1001/jama.286.11.1340
复制
发表时间：
2001-09-19
影响因子：
120.7
通讯作者：
McNellis, D
中科院分区：
文献类型：
--
作者：
Owen, J;Yost, N;McNellis, D
背景虽然子宫颈长度缩短一直与自发性早产有关，但尚不清楚妊娠期这种危险因素何时变得明显。目的确定妊娠16周至18周6天之间的超声子宫颈检查结果是否可预测自发性早产，以及妊娠23周6天的系列评估是否可提高高危妇女的预测。1997年3月至1999年11月，在美国9所大学附属医学中心对183名在妊娠32周前经历过自然分娩的单胎妊娠妇女进行了盲法观察研究。沿沿着闭合的颈管内测量从外口到功能性内口的宫颈长度。Funterm和动态宫颈缩短也recorded.Main结果测量自发性早产前35周的妊娠，分析所选择的截止值的宫颈length.Results 48名妇女（26%）经历了自发性早产前35周的妊娠。初次超声检查时宫颈长度小于25 mm与自发性早产的相对危险度（RR）为3.3相关。(95%置信区间[CI]，2.1-5.0;灵敏度=19%;特异性=98%;阳性预测值=75%）。在控制了宫颈长度后，漏斗长度（P= 0.24）和动态缩短（P= 0.054）均不是自发性早产的独立预测因子。然而，在系列评价中使用观察到的最短宫颈长度，在任何动态缩短后，宫颈长度小于25 mm的自发性早产的RR增加至4.5（95% CI，2.7-7.6;灵敏度=69%;特异性=80%;阳性预测值=55%）。在受试者工作特征曲线分析中，与孕16周至18周6天的单次宫颈测量相比，孕23周6天的连续测量显著提高了对自发性早产的预测结论在妊娠16周至18周6天内通过阴道超声评估宫颈长度，并通过系列评估进行补充，预测高危妇女妊娠35周前自发性早产。
Context Although shortened cervical length has been consistently associated with spontaneous preterm birth, it is not known when in gestation this risk factor becomes apparent.Objective To determine whether sonographic cervical findings between 16 weeks' and 18 weeks 6 days' gestation predict spontaneous preterm birth and whether serial evaluations up to 23 weeks 6 days' gestation improve prediction in high-risk women.Design, Setting, and Participants Blinded observational study performed between March 1997 and November 1999 at 9 university-affiliated medical centers in the United States in 183 women with singleton gestations who previously had experienced a spontaneous birth before 32 weeks' gestation.Observation Certified sonologists performed 590 endovaginal sonographic examinations at 2-week intervals. Cervical length was measured from the external os to the functional internal os along a closed endocervical canal. Funneling and dynamic cervical shortening were also recorded.Main Outcome Measure Spontaneous preterm birth before 35 weeks' gestation, analyzed by selected cutoff values of cervical length.Results Forty-eight women (26%) experienced spontaneous preterm birth before 35 weeks' gestation. A cervical length of less than 25 mm at the initial sonographic examination was associated with a relative risk (RR) for spontaneous preterm birth of 3.3.(95% confidence interval [CI], 2.1-5.0; sensitivity=19%; specificity=98%; positive predictive value=75%). After controlling for cervical length, neither funneling (P=.24) nor dynamic shortening (P=.054) were significant independent predictors of spontaneous preterm birth. However, using the shortest ever observed cervical length on serial evaluations, after any dynamic shortening, the RR of a cervical length of less than 25 mm for spontaneous preterm birth increased to 4.5 (95% CI, 2.7-7.6; sensitivity=69%; specificity=80%; positive predictive value=55%). Compared with a single cervical measurement at 16 weeks' to 18 weeks 6 days' gestation, serial measurements at up to 23 weeks 6 days significantly improved the prediction of spontaneous preterm birth in a receiver operating characteristic curve analysis (P=.03).Conclusions Cervical length assessed by endovaginal sonography between 16 weeks' and 18 weeks 6 days' gestation, augmented by serial evaluations, predicts spontaneous preterm birth before 35 weeks' gestation in high-risk women.