超声弹性成像技术预测自发性早产:Meta分析

目的 应用Meta分析评价超声弹性成像技术对自发性早产的预测价值.方法 检索PubMed、Cochrane Library、中国知网及万方医学网自1990年1月1日-2020年1月1日收录的超声弹性成像预测早产相关文献,按照纳入及排除标准进行筛选,并评价其质量.采用Meta-disc 1.4软件进行Meta分析.结果 ...     

妊娠中期宫颈弹性参数联合宫颈长度对自发性早产的预测价值

目的:评估妊娠中期宫颈软硬度特点,探讨宫颈弹性参数联合宫颈长度(CL)对自发性早产(sPTB)的预测价值。方法:回顾性分析2018年1月至2019年12月在成都市妇女儿童中心医院进行产前超声检查的147例足月产孕妇(足月产组)和24例sPTB孕妇(sPTB组)的临床资料。妊娠16～28周时采用经阴道超声E-Cervix...     

Accuracy of cervical transvaginal sonography in predicting preterm birth: a systematic review.

This review investigates the accuracy with which transvaginal cervical sonography predicts spontaneous preterm birth. Published studies were identified without language restrictions through nine different databases and manual searching of bibliographies of known primary and review articles. Studies were selected if they undertook antenatal transvaginal sonographic cervical assessment among a population of pregnant women with known gestational age of delivery. There were 46 primary articles, which included a total of 31,577 women, consisting of 33 studies in asymptomatic and 13 studies in symptomatic women. Data were extracted for the studies' characteristics and quality. Accuracy data were used to form 2 x 2 contingency tables for various cervical length measurements with birth before 32, 34 and 37 weeks' gestation as the reference standards. Data were stratified according to singleton or twin pregnancy, gestational age at testing, cervical length threshold, and the various reference standards, and were pooled to produce summary estimates of likelihood ratios (LRs). Our review showed that transvaginal cervical sonography identifies women who are at higher risk of spontaneous preterm birth, although there was a wide variation amongst studies with respect to gestational age at testing, definition of threshold of abnormality and definition of reference standard. The most commonly reported sub-group was testing of asymptomatic women at < 20 weeks' gestation using a threshold cervical length of 25 mm with spontaneous preterm birth before 34 weeks' gestation as the reference standard. The summary LR+ for this group was 6.29 (95% CI, 3.29-12.02), with corresponding LR- of 0.79 (95% CI, 0.65-0.95). Both cervical length measurement and funneling, whether alone or in combination, appear to be useful (depending on the threshold chosen to define the abnormality) in predicting spontaneous preterm birth in asymptomatic women. For symptomatic women there was a paucity of data, although the degree of funneling appeared to be predictive of spontaneous preterm birth.     

Comparison of transvaginal sonography in recumbent and standing maternal positions to predict spontaneous preterm birth in singleton and twin pregnancies.

OBJECTIVE: To evaluate whether serial transvaginal sonographic examination of the cervix with the woman in a standing position improves the prediction of spontaneous preterm birth (SPB) compared with the conventional posture. METHODS: For both a recumbent and upright maternal position, the inter- and intraobserver agreement of cervical length (CL) measurement was calculated. In 363 pregnancies at risk for SPB, we determined prospectively CL and funnel width (FW) including differences between the positions and between longitudinal measurements from 15 weeks onwards. Multivariate logistic regression analysis, contingency tables and receiver-operating characteristics (ROC) curves were used. Data were stratified according to singleton or twin pregnancy, maternal position, gestational age at examination and different cut-off values to predict SPB < 36 weeks. RESULTS: The interobserver variability in each position was similar, with an interclass correlation coefficient (95% CI) of 0.952 (0.811-0.984) in the recumbent and 0.942 (0.837-0.978) in the upright maternal position. After exclusion of pregnancies with iatrogenic preterm birth, 15/138 (11%) singletons and 29/153 (19%) twin pairs were born at <36 weeks. The incidence of funneling was greater in an upright compared with a recumbent maternal position by 12.3% in singleton and 13.1% in twin pregnancies before 25 weeks, and by 13.0% and 21.6% between 25 and 30 weeks, respectively. This resulted in an earlier and more accurate prediction of SPB by transvaginal ultrasound in an upright compared with a recumbent maternal position, which could be shown by all applied statistical methods. The influence of posture on the prognostic value of the CL varied depending on the cut-off value. Differences in CL or FW between 15-20 and 25-30 weeks predicted SPB better than did differences between shorter intervals. CONCLUSIONS: Evaluation of the cervix with the woman in the upright position permits earlier detection of funneling. This may enable earlier and more appropriate intervention to avoid SPB.     

超声技术评估妊娠宫颈在预测早产中的应用进展

早产是全球5岁以下儿童死亡的第二大原因,目前已成为衡量一个国家的健康指标之一,有效的筛查手段能提高早产的防治水平.超声具有无辐射、适用性广及操作简便等优势,已成为临床评估早产的重要手段.本文就超声技术评估妊娠宫颈在预测早产的应用现状及进展进行综述.     

Does transvaginal sonographic measurement of cervical length before 14 weeks predict preterm delivery in high-risk pregnancies?

OBJECTIVE: To determine whether high-risk patients manifest cervical length < 25 mm on transvaginal ultrasound before 14 weeks of gestation, and if this finding is predictive of preterm delivery. METHODS: Asymptomatic pregnancies at high risk for preterm birth were followed prospectively from 10 + 0 weeks to 13 + 6 weeks with transvaginal sonographic measurement of the cervix. A cervical length < 25 mm was considered a short cervix at this gestational age and at the follow-up ultrasound examinations, performed between 14 and 24 weeks. The primary outcome was preterm birth at < 35 weeks of gestation. RESULTS: One hundred and eighty-three pregnancies met the study criteria and were included in the analysis. Only 10 (5%) patients had a cervix < 25 mm before 14 weeks. The sensitivity, specificity and positive and negative predictive values of a short cervix were 14%, 97%, 50%, and 82%, respectively (relative risk, 2.8; 95% confidence interval, 1.4-5.6). The mean transvaginal sonographic cervical length before 14 weeks of gestation was 33.7 +/- 6.9 mm in pregnancies which delivered preterm (n = 36), and 35.0 +/- 6.8 mm in those delivering at term (n = 147) (P = 0.3). Follow-up transvaginal ultrasound examination of the cervix to 24 weeks revealed that the average gestational age at which a short cervix was detected was 18.7 +/- 2.9 weeks. CONCLUSION: A cervical length < 25 mm on transvaginal sonographic assessment rarely occurs before 14 weeks even in high-risk patients destined to deliver preterm; in these patients cervical changes predictive of preterm birth develop mostly after this gestational age.     

A comparison of two different ultrasound methods for estimating fetal weight in preterm gestations

A prospective study was conducted to evaluate the estimation of fetal weight in preterm pregnancies by use of ultrasound measurements. Two equations for estimating fetal weight, one proposed by Shepard and associates and the other by Hadlock and associates, were evaluated. The ability to estimate fetal weight accurately was evaluated with respect to birth weight and menstrual age. Shepard's equation is associated with a lower mean signed percent error than Hadlock's, when the birth weight is less than 1500 g (4% vs 12%) or when the menstrual age is between 23 weeks to 30 weeks (2% vs 10%). However when the birth weight is between 1500 g and 3500 g, or the menstrual age is between 31 weeks to 36 weeks, Hadlock's equation has a lower mean signed percent error: 1% vs -4% for the birth weight category and 2% vs -3% for the menstrual age category. In preterm gestations both equations estimate fetal age weight with a low mean signed percent error--Shephard's -0.4% versus Hadlock's 6.0%.     

Vaginal progesterone to prevent preterm birth in high-risk women

Preterm birth is a significant problem in the United States, contributing to neonatal morbidity and mortality. Progesterone is a hormone naturally produced by the corpus luteum and the placenta in early pregnancy and is essential for maintaining pregnancy. Clinicians and researchers have used this hormone in later gestation to try to prevent preterm birth. However, mechanisms of action, indications for use, dosing and administration have varied and are not fully understood. This article revisits two recent randomized controlled trials in which researchers investigated the effectiveness of vaginal progesterone suppositories and gel in the prevention of preterm birth among women who were at high risk for delivering prematurely.     

中期妊娠剪切波弹性成像预测双胎妊娠自发性早产

目的 观察剪切波弹性成像(SWE)于中期妊娠预测双胎妊娠自发性早产(SPTB)的价值.方法 前瞻性纳入86名产前超声诊断为双胎妊娠的孕妇,于中期妊娠分别采用常规超声及SWE测量宫颈长度(CL)及剪切波速度(SWV),观察其预测SPTB的效能.结果 最终51名孕妇发生SPTB(SPTB组)、35名未发生SPTB(非SPT...     

Sonographic measurement of cervical length in threatened preterm labor in singleton pregnancies with intact membranes.

OBJECTIVES: To predict when delivery will occur, within 48 h and 7 days of presentation and before 35 weeks' gestation in women presenting with threatened preterm labor. METHODS: Sonographic measurement of cervical length was carried out in 510 women with singleton pregnancies presenting with threatened preterm labor and intact membranes at 24 to 33 + 6 weeks of gestation. The measurement was not taken into account in the subsequent management of the pregnancies. The outcome measures were delivery within 48 h and 7 days of presentation and delivery before 35 weeks. RESULTS: The median gestation at presentation was 30 + 1 (range, 24 to 33 + 6) weeks and the median cervical length was 25 (range, 1-51) mm. Delivery within 48 h of presentation occurred in 21 (4.1%) cases, delivery within 7 days occurred in 43 (8.4%) and delivery before 35 weeks occurred in 76 (14.9%). Logistic regression analysis demonstrated that the only significant independent predictor of delivery within 48 h was cervical length (odds ratio (OR), 0.73; 95% CI, 0.65-0.81) and for delivery within 7 days the independent predictors were cervical length (OR, 0.69; 95% CI, 0.63-0.76) and vaginal bleeding (OR, 19.42; 95% CI, 3.87-97.4). In the subgroup of women who did not deliver within 7 days of presentation, the incidence of delivery before 35 weeks was 7.1% (33 of 467) and the only significant independent predictor of such delivery was cervical length (OR, 0.92; 95% CI, 0.88-0.96, P < 0.0001). There was no significant independent contribution to any of the outcome measures from ethnic group, maternal age, gestational age, body mass index, parity, cigarette smoking or use of tocolytics. CONCLUSIONS: In women with threatened preterm labor sonographic measurement of cervical length helps to distinguish between true and false labor and to predict early preterm delivery.     

Sonographic cervical length in singleton pregnancies with intact membranes presenting with threatened preterm labor.

OBJECTIVE: Less than 10% of women presenting with preterm contractions progress to active labor and delivery. This study investigates whether cervical length measurements by ultrasound can discriminate between true and false labor in women presenting with threatened preterm labor. METHODS: Cervical length was measured by transvaginal ultrasound in 253 women with singleton pregnancies presenting with painful uterine contractions at a median age of 31 (range, 24-35) weeks of gestation. Women presenting in active labor, defined by the presence of cervical dilatation of >or = 3 cm, those with ruptured membranes and those that underwent prior or subsequent cervical cerclage were excluded from the study. The clinical management was determined by the attending obstetrician without taking into account the cervical length. Primary outcome of the study was delivery within 7 days of presentation based on the results of randomized studies on the use of tocolytics in women with preterm labor that reported a prolongation of pregnancy by 7 days. RESULTS: Delivery within 7 days of presentation occurred in 21/253 (8.3%) pregnancies and this was inversely related to cervical length. Receiver-operating characteristics (ROC) curves established a cervical length of 15 mm as the most relevant cut-off level for the prediction of preterm delivery within 7 days. In 217 cases the cervical length was > or = 15 mm and only four of these (1.8%) delivered within 7 days. In the 36 women with cervical length < 15 mm, delivery occurred in 17 (47.2%) within 7 days. Logistic regression analysis demonstrated that significant independent contribution in the prediction of delivery within 7 days was provided by cervical length, contraction frequency at presentation, previous history of preterm delivery and vaginal bleeding. There was no significant contribution from gestation at presentation, ethnic origin, maternal age, parity, cigarette smoking or the administration of tocolysis, antibiotics or steroids. Similar results were shown in a subanalysis of 162 patients presenting at a gestational age below 32 weeks: 9/19 patients (47.4%) with a cervical length below 15 mm delivered within 7 days compared to 3/143 (2.1%) with a cervical length > or = 15 mm. Univariate as well as multivariate analyses confirmed cervical length to be a significant independent predictor of delivery within 7 days in this population. CONCLUSIONS: Sonographic measurement of cervical length helps to avoid overdiagnosis of preterm labor in women with preterm contractions and intact membranes.     

超声E-cervix技术评估宫颈机能对早产预测效能的ROC曲线分析

目的 探讨超声E-cervix技术评估宫颈机能对早产预测效能分析。方法 选取2020年1月～2021年1月200例在我院建档规律接受产检孕妇及100例孕前常规检查者,采用超声E-cervix技术评估宫颈机能,根据早产情况分为早产组和足月产组,比较两组一般资料、宫颈长度（CL）、弹性对比指数（ECI）、宫颈外口应变率（EOS）、宫颈内口应变率（IOS）、宫颈内外口应变比值（IOS/EOS）、硬度比值（HR）,采用多因素Logistic回归方程分析早产的相关影响因素,采用受试者工作特征曲线（ROC）分析超声E-cervix技术参数预测早产的价值。结果 早产组宫颈手术史高于足月产组（P＜0.05）;妊娠期者CL、IOS、IOS/EOS高于增生期、分泌期者,HR低于增生期、分泌期者（P＜0.05）;早产组CL、HR低于足月产组,ECI、IOS、IOS/EOS高于足月产组（P＜0.05）;宫颈手术史、ECI、IOS、IOS/EOS是早产的相关危险因素,CL、HR是早产的相关保护因素（P＜0.05）;CL、ECI、IOS、IOS/EOS、HR预测早产的ROC曲线下面积依次为0.802、0.745、0.795、0.795、0.803,各参数联合的ROC曲线下面积为0.803。结论 ECI、IOS、IOS/EOS是早产的相关危险因素,CL、HR是早产的相关保护因素,超声E-cervix技术可检测以上参数评估宫颈机能,从而对早产做出准确预测。     

A comparison of mammographic, sonographic and histologic parameters in breast cancer

Sonography provides a safety in dignity that is comparable to mammography while its overall sensitivity is higher. Mammography remains the method of choice. All mammographically unclear cases should be elucidated with sonography. For this reason an integration of a sonographic device and a mammography unit is advisable.     

Hyaluronan in cervical epithelia protects against infection-mediated preterm birth

Increased synthesis of cervical hyaluronan (HA) from early to late pregnancy has long been proposed to play an essential role in disorganization of the collagen-rich extracellular matrix to allow for maximal compliance and dilation of the cervix during the birth process. Here, we show that HA is not essential for increased cervical distensibility during late pregnancy. Rather, cervicovaginal HA plays an unanticipated important role in epithelial barrier protection of the lower reproductive tract. Specifically, HA depletion in the cervix and vagina resulted in inappropriate differentiation of epithelial cells, increased epithelial and mucosal permeability, and strikingly increased preterm birth rates in a mouse model of ascending vaginal infection. Collectively, these findings revealed that although HA is not obligatory for cervical compliance, it is crucial for maintaining an epithelial and mucosal barrier to limit pathogen infiltration of the lower reproductive tract during pregnancy and thereby is protective against infection-mediated preterm birth.     

Cervical length screening for predicting preterm birth: A comparative review of guidelines

A cervical length (CL) assessment may predict preterm birth (PTB). This study aimed to analyze and compare the recommendations of guidelines on the role of CL in the prediction of PTB. There is no consensus regarding universal screening of asymptomatic women without a history of prior spontaneous PTB (sPTB), using CL. On the other hand, CL assessment is recommended in cases with a history of sPTB due to the high recurrence rate. Finally, there is discrepancy regarding CL assessment in asymptomatic women with multiple pregnancy. Although far from perfect, CL measurement remains the best available method to predict PTB.     

Prediction of preterm birth by second trimester cervical sonography in twin pregnancies.

OBJECTIVES: To determine the predictive value of sonographic cervical length and of funneling for spontaneous preterm delivery (PTD) in twin pregnancies under 26 weeks' gestation. METHODS: Women with twin pregnancies were studied prospectively with transvaginal or translabial ultrasound of the cervix from 18 to 26 weeks' gestation. Exclusion criteria were: signs of preterm labor, prophylactic cervical cerclage, placenta previa, or severe congenital fetal anomaly. The primary outcome was spontaneous preterm birth at < 35 weeks' gestation. RESULTS: Sixty-five twin pregnancies were analyzed, of which 23% (15/65) delivered preterm. Cervical ultrasound examination was performed by 22 weeks' gestation in 75% and by 24 weeks' gestation in 91% of women. Cervical length < or = 25 mm and < or = 30 mm was associated with sensitivities of 27% and 53%, respectively, and with 67% and 62% rates of PTD, respectively (R.R. 4.6, C.I. 2.0-10.3 and R.R. 3.6, C.I. 1.6-7.8, respectively). A cervical length > 35 mm was associated with only a 4% rate of PTD (R.R 0.13; C.I. 0.02-0.93). Of 10 women (15%) with any cervical funneling, 70% delivered preterm, all under 32 weeks' gestation. By logistic regression analysis, both short cervix < or = 30 mm and any funneling were strongly predictive of PTD. CONCLUSIONS: Both cervical length < or = 30 mm and cervical funneling in twin pregnancies under 26 weeks' gestation are independently and strongly associated with high risk for preterm birth. A long cervix, of length > 35 mm, is associated with very low risk (4%) for preterm birth.     

Dynamic cervical change: is real-time sonographic cervical shortening predictive of preterm delivery in patients with symptoms of preterm labor?

OBJECTIVES: To determine prospectively if dynamic cervical change (spontaneous real-time cervical shortening) is predictive of preterm delivery at < 37 weeks' gestation in patients with symptoms of preterm labor. METHODS: This was a prospective study of patients at 23-34 weeks' gestation who were symptomatic for preterm labor. Patients underwent a 10-min real-time sonographic cervical length assessment with measurements taken at 1-min intervals. The presence or absence of dynamic cervical change, defined as real-time changes in cervical length observable to the naked eye of the sonologist during the examination, was recorded. Gestational age at delivery was obtained from medical records. Preterm delivery was defined as delivery at < 37 weeks' gestation. Dynamic cervical change and initial and minimum cervical lengths were assessed for prediction of preterm delivery. RESULTS: Seventy-six patients were enrolled, and 66 were available for outcome analysis. Thirty-one patients (47%) exhibited dynamic cervical change. Patients with dynamic change had shorter initial cervical lengths (27 mm vs. 36 mm, P = 0.001), shorter minimum cervical lengths (20 vs. 33 mm, P < 0.001) and larger changes in cervical length during the examination period (10 vs. 4 mm, P < 0.001). In the subgroup of patients with an initial cervical length > 30 mm, those with dynamic change delivered earlier than did those without dynamic change (36.8 vs. 38.6 weeks, P = 0.02), and a higher percentage delivered preterm (27% vs. 11%, odds ratio (OR), 3.0 (0.5-17.0)). Multivariate analysis showed that minimum cervical length was a better predictor of preterm delivery than was initial cervical length. CONCLUSIONS: Dynamic cervical change occurs frequently in association with shortened cervical length. In patients with longer initial cervical lengths, dynamic change may increase the risk for preterm delivery. When dynamic change is noted in a patient with preterm labor symptoms, use of the minimum cervical length observed may be better compared with initial cervical length for determining preterm delivery risk.     

超声评估宫颈预测早产的新进展

早产是导致围生儿死亡及新生儿疾病的主要原因,是临床工作中经常出现的难题.全球早产的发生率约11.1％[1], 2016年国内一项统计报道早产的发生率约为9.9％[2].我国二胎政策开放后,新生儿出生率正逐渐增高,产妇早产的发生率也有所增加.