Prediction of fetal lung maturity: inaccuracy of study using conventional ultrasound instruments

The ability of three ultrasound (US) parameters--echogenicity, texture, and through transmission--to predict fetal lung maturity was tested in 59 patients using currently available clinical US equipment. The chi square test was used to determine whether there was an association between any single parameter and a "mature" lecithin/sphingomyelin (LS) ratio or specific phosphatidycholine (SPC). Multiple linear regression analysis was used to assess the combined ability of these three parameters and gestational age to predict LS ratio and SPC. There was no correlation between fetal lung maturity, as determined by mature LS and SPC indices, and the US parameters tested using unmodified clinical equipment.     

Ultrasound prediction of fetal lung maturity

Amniocentesis for determination of fetal lung maturity and ultrasonographic (US) evaluation of the biparietal diameter (BPD) and placental grade were performed simultaneously in 261 nondiabetic pregnant women. A BPD of at least 9.3 cm and a grade 3 placenta were evaluated as predictors of fetal lung maturity using amniotic fluid phospholipids as indicators of a mature lung profile. The ability of the sonographic parameters to predict fetal lung maturity was closely related to menstrual age. Before 37 weeks, the false-positive prediction rate using a grade 3 placenta was 100%, and the false-positive prediction using the BPD was 85.6%. After 37 weeks, the false-positive rate using a grade 3 placenta was 5.9%, and the false-positive rate using the BPD was 9.5%. Thus menstrual age, and not these two US parameters, dictated fetal lung maturity. The authors conclude that the best use of US for predicting fetal lung maturity is in establishing menstrual age early in pregnancy.     

Echogenicity of fetal lung: relation to fetal age and maturity

Reports of echogenicity of the fetal lung as it relates to maturity of that organ are scant and at variance. A study was undertaken to determine if any correlation between fetal age and/or lung maturity and echogenicity could be determined in a clinical setting. Studies were performed with either linear array or mechanical sector real-time devices. Echogenicity of the fetal lung was compared with that of the fetal liver in the same longitudinal (parasagittal or coronal) sonogram. Lung echogenicity was judged to be hypodense, isodense, slightly hyperdense, or markedly hyperdense as compared with the liver texture. One hundred eighty-five studies were evaluated; of these, some 37 patients also underwent amniocentesis for determination of lecithin/sphingomyelin ratios (L/S) and presence of phosphatidyl glycerol (PG). Linear regression analyses were performed to determine if lung echogenicity would serve as an indicator of fetal maturity. No clinically applicable relation was established between fetal lung echogenicity and gestational age, L/S, or presence of PG in amniotic fluid with current methodology. The possibility persists that tissue characterization techniques may find application in such an investigation.     

Prediction of birthweight by fetal ultrasound biometry.

A total of 104 women with singleton pregnancies who were delivered between 37 and 42 weeks gestation had ultrasound scans during the fortnight before delivery. The biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL) were measured in all cases. Estimation of fetal weight (EFW) was done by four different methods: using AC alone, AC/BPD, AC/FL and AC/BPD/FL. Results were compared with values of actual birthweights at delivery. There was no significant difference between the mean birthweights of the 47 boy and 57 girl fetuses studied. The EFW(Shepard) method showed the least bias overall: mean percentage error 1.7%, standard deviation (SD) 10.6%. The other three methods significantly underestimated birthweights on average: EFW(Deter), mean error 2.2%, SD 9.3%, p < 0.02; EFW(Campbell), mean error 5.4%, SD 9.5%, p < 0.001; EFW(Hadlock), mean error 5.6%, SD 9.3%, p < 0.001. The percentage error in each group was significantly negatively correlated (p < 0.001) with the scan-delivery interval. Two new equations were generated which gave more accurate predictions for the cases under study using AC, BPD and FL as a combination and also in addition to scan-delivery interval (SDI) in days.     

Epiphyseal ossification centers in the assessment of fetal maturity: sonographic correlation with the amniocentesis lung profile

The epiphyseal ossification centers of the distal femur (DFE) and proximal tibia (PTE) appear and enlarge during the third trimester of pregnancy. Late in the third trimester, the epiphysis of the proximal humerus (PHE) begins to ossify in some fetuses. Using the amniocentesis lung profile to determine the value of sonographic epiphyseal visualization as a predictor of pulmonary maturity, we studied 50 fetuses prospectively and compared the sonographic epiphyseal findings with results from the amniocentesis lung profiles. Nine fetuses with a visible PHE had a mature amniocentesis lung profile (accuracy of positive prediction = 100%), and then fetuses with an immature amniocentesis lung profile had no visible PHE (conegativity = 100%). Fetuses in which the combined DFE and PTE diameters were greater than 11 mm or in which the DFE and the PTE diameters were similar in size (DFE less than or equal to 1 mm larger than PTE) also yielded positive results. Copositivity and accuracy of prediction of an immature amniocentesis lung profile, on the other hand, were low (22%-25%) for the same epiphyseal parameters. These data suggest that antenatal visualization and measurement of the epiphyseal ossification centers of the fetal knee and shoulder may help to identify fetuses that would have a mature amniocentesis lung profile.     

Magnetic resonance assessment of fetal lung maturity: comparison between signal intensity and volume measurement

Purpose

We evaluated the associations between gestational age (GA) and lung-to-liver signal intensity ratio (LLSIR) and fetal lung volume (FLV) using magnetic resonance imaging (MRI). Moreover, we evaluated the reproducibility of these measurements.

Materials and methods

LLSIR and FLV were measured using single-shot fast spin-echo MRI in 88 consecutive fetuses. The Spearman test was used to assess the relationships between (1) LLSIR and GA, and (2) FLV and GA in 81 fetuses without lung abnormalities. Intra- and inter-observer reliabilities were assessed using intra-class correlation coefficients (ICCs).

Results

Overall, GA and LLSIR were significantly correlated (r?=?0.62, p?<?0.001). However, GA and LLSIR were only significantly correlated during the third trimester (before third trimester: r?=?0.39, p?=?0.08; during third trimester: r?=?0.46, p?<?0.001). Overall, GA and FLV were significantly correlated (r?=?0.72, p?<?0.001). FLV was significantly correlated with GA before (r?=?0.86, p?<?0.001) and during the third trimester (r?=?0.47, p?<?0.001). All ICCs were above 0.90.

Conclusions

LLSIR and FLV are useful for the assessment of fetal lung maturity and are highly reproducible. Before the third trimester, FLV is more suitable than LLSIR for the evaluation of fetal lung maturity.

     

胎儿全前脑畸形的超声诊断分析

现将我院近5年产前超声检查后经引产或产后CT证实的10例HPE畸形分析如下。     

Determination of skeletal maturity by ultrasound: a preliminary report

Objective Replacement of radiography by sonography for determination of skeletal maturity.Design Sonographic and radiographie evaluation of the maturation of the iliac bone apophysis (Risser's sign) and evaluation of the distal radial epiphyses.Patients 64 children and adolescents with idiopathic scoliosis, aged from 5 to 19 years.Results Sonograms with corresponding radiographs were available for the hand and wrist in 36 cases and for the iliac bone in 28 cases. Comparison of sonographic with radiological data revealed sonography to have a sensitivity for qualifying the status of the distal radial epiphysis of 93.1%. Specificity was 100%, accuracy 94.4% for investigation of the distal radial epiphysis. Overall accuracy for correct determination of Risser's stage by ultrasound (in comparison with the radiographie standard) was 89.2%.Conclusions These findings suggest that ultrasound is a useful and highly acceptable tool for bone age determination in clinical routine or screening studies and will help to reduce ionizing radiation to children and adolescents.Scientific Award in Pédiatrie Orthopaedics 1995 of the German- Austrian-Swiss Ped. Orthopaedic Association     

超声检查胎儿成熟度的方法

胎儿成熟度的判断在高危妊娠管理中有非常重要的意义。许多高危孕妇需要采用计划分娩提前终止妊娠,在保证孕产妇安全的前提下,围产儿能否存活,取决于胎儿成熟度,更重要的是胎肺的成熟度。胎肺是胎体重要器官,其成熟度标志着胎儿能否在子宫外存活。因此,在高危妊娠计划分娩前,了解肺成熟度是提高早产儿成活率的关键。目前胎儿成熟度的测定方法有多种,主要为胎肺成熟度的测定。以下就胎肺成熟度的检查方法进行综述。     

胎儿脐膨出的超声诊断价值

胎儿脐膨出是一种较少见的先天性畸形,为先天性腹壁发育不全,周光萱等报告其发病率为2·18/万[1],膨出的类型与预后关系密切,故胎儿时期诊断脐膨出并判断类型,可提高优生率,减少新生儿出生缺陷,减轻家庭负担。1材料与方法搜集2001年12月~2005年2月超声拟诊为胎儿脐膨出15例,生后新生儿或引产后男11例,女4例,12例为脐膨出,3例为腹裂,最早为孕20周发现。采用美国生产的Acuson Sequoia 512彩色多普勒超声诊断仪,探头频率为3.5MHz、5.0MHz,采用胎儿腹部横切面、纵切面等多切面观察,找到脐带发出处,观察脐部膨出包块是否有完整包膜、内容物及…     

Quantitative and qualitative evaluations of fetal lung with MR imaging

PURPOSE: To measure both volume and signal intensity of the fetal lung at magnetic resonance (MR) imaging and to evaluate the clinical use of this method to predict fetal pulmonary hypoplasia. MATERIALS AND METHODS: A total of 87 fetuses evaluated with MR imaging at 24-39 weeks of gestation were classified into a control group with good respiratory outcome (group A, n = 58) or a poor outcome group with severe respiratory disturbance after birth (group B, n = 29). Planimetric measurement of total lung volume and calculation of the ratio of lung signal intensity to spinal fluid signal intensity (L/SF) were performed on MR images by using region-of-interest analysis. Regression analysis, analysis of covariance, analysis of variance, and receiver operating characteristic (ROC) analysis were performed. RESULTS: The best fit for group A lung volume was represented by the regression line V = (2.41 x G) - 37.6 (r = 0.537, P <.001), in which V is lung volume and G is gestational weeks; that for group B, by V = (0.97 x G) - 14.0 (r = 0.378, P <.05). Results of analysis of covariance with gestational weeks used as a covariate showed a significant difference in lung volume between the two groups (P <.001). Mean +/- SEM for L/SF ratio was 0.817 +/- 0.013 and 0.598 +/- 0.019 in groups A and B, respectively (P <.001). For prediction of postnatal respiratory outcome, the area under the ROC curve for lung volume and L/SF ratio combined was 0.990, significantly higher than that for lung volume alone (P <.05). CONCLUSION: Simultaneous measurement of fetal lung volume and signal intensity on MR images is a promising method for predicting fetal pulmonary hypoplasia.     

超声诊断胎儿畸胎瘤1例

患者 女，25岁。停经28周余，于2003年8月21日来我院就诊。主诉：首次妊娠，末次月经2003年2月3日。无腹疼及阴道流血等不适。     

诊断超声对胎儿角膜的影响

将 90名早孕妇女 (孕 8～ 12周 )随机分为 3组 :Ⅰ组 (对照组 ) ;Ⅱ组 (超声辐照 3min组 ) ;Ⅲ组 (超声辐照 2 0min组 )。采用诊断超声辐照人体宫内胎儿 ,2 4h后取胎儿角膜做透射电镜及组织化学研究。结果表明 :诊断超声辐照 3min ,胎儿角膜出现水肿改变 ,SDH(琥珀酸脱氢酶 )活性下降 (P <0 .0 5 ) ;辐照 2 0min ,角膜结构明显损伤 ,SDH活性下降显著 (P <0 .0 1)