超声动态监测胎儿肾盂分离的意义

目的超声动态监测妊娠中晚期肾盂分离的特点和程度,判断生理性或梗阻性肾盂积水。方法对妊娠16～42周发现胎儿肾脏肾盂分离前后径(APD)≥5mm者进行超声动态监测,同时仔细检查肾盂出口处宽度、肾盏、输尿管、膀胱。若肾盂分离持续存在,出生后再次检查。结果在孕30周以前APD<6mm(排除染色体异常),孕30周以后APD<7mm,单纯肾盂分离,大多可恢复正常;反之且伴肾盂出口处宽度>7mm,肾盂分离饱满呈楔状,则需在出生后2天随访。孕30周以后APD>15mm,伴肾盏扩张、输尿管扩张、膀胱持续增大,则高度提示泌尿道梗阻。结论超声动态监测胎儿肾盂分离能较早区别生理性与病理性泌尿系梗阻病变。     

超声诊断胎儿重复肾1例

孕妇，22岁。孕1产0，孕33周，外院超声诊断胎儿右肾盂积水，来我院检查，超声显示：宫内单胎，头位，胎儿头围、腹围、股骨长及肱骨长符合孕周，右侧壁胎盘，AFI150mm，纵切位显示胎儿双侧肾内均可见互不相连的上下两个肾盂回声，右肾上肾盂扩张，横切位显示扩张的上肾盂宽17mm，下肾盂大小正常，     

胎儿肾盂宽度的超声研究

目的探讨不同孕周胎儿肾盂宽度的正常参考范围及胎儿肾盂积水的诊断标准。方法选取来我院做产前超声检查的中、晚期妊娠胎儿共5988个肾脏作为研究对象,观察并记录肾盂宽度,经统计学处理制定胎儿不同孕周。肾盂宽度的正常参考范围。结果胎儿不同孕周肾盂宽度均呈正偏态分布。其正常参考范围为：16-19周,≤0.23cm;20-23周,≤0.46cm;24-27周,≤0.74cm：28-31周,≤0.94cm;32-35周,≤1.08cm;36-39周,≤1.18cm;≥40周,≤1.20cm。结论胎儿不同孕周肾盂宽度有一定的正常范围可参考,大于正常参考范围可诊断为肾积水。胎儿轻至中度。肾积水多数是一个可恢复性的过程。     

1例胎儿畸形（肾盂积水）致梗阻性难产的护理

患者女性,30岁,平素月经规律,4～5 d/28～30 d,预产期为2007年5月10日,孕期定时产检,无毒物及动物接触史,孕早期未使用药物,孕期查血糖为正常范围,未做唐氏儿检查,血常规检查血HGB 100 g/L,其余各项均在正常范围,孕21周产检超声发现：胎儿双肾分离（正常胎儿肾脏的集合系统可有轻度分离,分离径可达6mm,而胎龄大于30周后肾盂扩张≥10 mm或存在肾小盏扩张则为肾积水）,右侧前后径约3.8 cm,左侧前后径约1.3 cm,右肾实质受压变薄,厚约0.3 cm,左肾实质厚约0.7 cm.     

超声测量肾盂角在诊断胎儿马蹄肾中的应用价值

目的评价超声测量胎儿肾盂角在产前诊断胎儿马蹄肾中的应用价值。方法 32例马蹄肾胎儿为马蹄肾组,正常中晚孕胎儿200例为对照组,建立正常胎儿肾盂角范围并分析其与孕周相关性;并将对照组胎儿与已证实为马蹄肾胎儿的肾盂角进行比较,分析肾盂角在诊断马蹄肾的敏感性及特异性。结果对照组胎儿中孕期肾盂角(171±7)°,晚孕期(163±6)°,马蹄肾组肾盂角中孕期(110±10)°,晚孕期(100±11)°;马蹄肾组肾盂角较对照组小(P0.05)。对照组胎儿肾盂角与孕周呈负相关;以肾盂角140°为界,诊断胎儿马蹄肾的敏感性为97%,特异性为100%。结论超声观测肾盂角在诊断胎儿马蹄肾中有重要作用。     

胎儿肾盂分离超声测值与预测转归的价值

目的分析不同孕周胎儿肾盂分离(APD)的超声测值及临床预后。方法对2013年1月至2015年10月在苏州大学附属第二医院产前超声检查诊断为肾盂分离的182例胎儿均随访至产后12个月,分析最终发展为不可复性肾积水胎儿首次检出孕周及肾盂APD值。结果 182例胎儿中孕期首次检出肾盂分离46例,晚孕期首次检出肾盂分离136例(双侧肾盂分离92例)。随访过程中,114例肾盂分离在胎儿期自行恢复,52例在出生后12个月内恢复,仅16例(8.8%,16/182)发展为不可复性肾积水。16例不可复性肾积水胎儿中10例(62.5%,10/16)于中孕期检出肾盂分离,肾盂APD测值7.4~11.5 mm,平均(9.6±1.5)mm;6例(37.5%,6/16)于晚孕期检出肾盂分离,肾盂APD测值13.6~14.8 mm,平均(12.8±2.0)mm。结果显示,中孕期检出肾盂分离胎儿的肾盂APD测值小于晚孕期检出肾盂分离的胎儿,且中孕期检出肾盂分离的胎儿预后较差,其发展为不可复性肾积水的胎儿(21.7%,10/46)多于晚孕期检出者(4.4%,6/136)。结论产前超声动态观察胎儿肾盂径线,并结合首次检出肾盂分离的孕周及肾盂APD测值,有助于预测胎儿预后。     

胎儿肾盂分离的主要原因及临床预后研究进展

胎儿肾盂分离是产前超声中较常见的表现,其中男胎儿肾盂分离发生率较女胎儿高,大多数由生理性因素所导致,常常呈一过性表现,随着孕周增大逐渐恢复或出生后自行消失;少数由病理因素所导致。病理性因素通常包括泌尿系结构异常、染色体异常、基因组拷贝数变异及基因变异。肾盂分离原因、程度及是否合并其他异常与胎儿预后显著相关,密切随访、早期识别病理性肾盂分离,有助于及时实施干预措施,改善和提高患儿预后。     

胎儿肾盂积水超声检查的作用

由于高分辨力超声诊断仪的广泛应用 ,近年来胎儿肾盂积水的超声诊断阳性检出率明显增加[1,2 ] 。随着临床技术的进步 ,出生前对胎儿施行干预措施成为可能[2 ] 。本文就如何准确地做出产前胎儿肾盂积水的诊断 ,如何适当进行产前干预 ,以及如何进行预后评价和产后处理等方面进行讨论。一、胎儿肾盂积水的研究背景输尿管芽于孕 5周时以指数速度快速分支发育成肾单位 ,于妊娠中期 80 %的肾单位分化完成 ,孕 3 6周时发育全部完成。尿液产生开始于孕 8周 ,但胎儿的肾脏在排泄废物和维持体内平衡方面只起很小的作用 ,而胎盘起着主导作用。胎儿尿液…     

超声诊断胎儿后尿道瓣膜1例

患者女,23岁。孕24周,孕1产0。来院常规超声检查所见:胎头双顶径53.7mm,可见胎心( ),胎儿心率167次/min,胎动( ),脊柱连续完整,股骨长33.9mm。羊水最大深度64.5mm,前壁胎盘。胎儿双肾增大,轮廓不清晰,肾实质明显变薄,左肾大小约48.7mm×24.2mm,右肾大小约44.4mm×26.3mm,双肾盂肾盏明显扩张,左肾盂分离16.2mm,右肾盂分离17.7mm,双侧输尿管显示不清晰。腹腔为一巨大无回声区占据,大小为64.9mm×77.9mm,壁厚4.3mm,回声增强,后尿道明显扩张,前后径10.1mm,与无回声区相连,似“钥匙孔”样改变。超声诊断:单胎中期妊娠,胎儿畸形(后尿道瓣膜可能性…     

超声对胎儿肾盂积水的观察及其临床意义

目的:探讨超声对胎儿肾盂积水的观察及其临床意义。方法:选取我院2012年7月²014年1月接诊的疑似胎儿肾盂积水的113例孕妇作为研究对象,皆采取超声观察,观察孕周202014年1月接诊的疑似胎儿肾盂积水的113例孕妇作为研究对象,皆采取超声观察,观察孕周20⁴0周;主要对胎儿肾盂形态与大小、肾皮质厚度、肾盏变化等进行观察与测量,同时进行分级并随访。结果:本次研究113例孕妇经超声观察后显示胎儿肾盂积水104例,其中Ⅰ级胎儿肾盂积水72例(93只肾),肾盂前后径0.3140周;主要对胎儿肾盂形态与大小、肾皮质厚度、肾盏变化等进行观察与测量,同时进行分级并随访。结果:本次研究113例孕妇经超声观察后显示胎儿肾盂积水104例,其中Ⅰ级胎儿肾盂积水72例(93只肾),肾盂前后径0.31¹.05 cm;Ⅱ级胎儿肾盂积水23例(26只肾),肾盂前后径1.141.05 cm;Ⅱ级胎儿肾盂积水23例(26只肾),肾盂前后径1.14¹.83 cm;Ⅲ级胎儿肾盂积水5例(5只肾),肾盂前后径1.531.83 cm;Ⅲ级胎儿肾盂积水5例(5只肾),肾盂前后径1.53³.31 cm;Ⅳ级胎儿肾盂积水4例(5只肾),肾盂前后径1.563.31 cm;Ⅳ级胎儿肾盂积水4例(5只肾),肾盂前后径1.56⁷.22 cm。随访结果表明Ⅰ级与Ⅱ级预后好,而Ⅲ级及以上产后大部分需要手术治疗。结论:胎儿肾盂积水比较常见,其中又以Ⅰ级与Ⅱ级居多且预后好,基本无需随访监测,Ⅲ级及以上虽然少见但产后需要手术治疗,往往需要随访监测。     

Serial translabial sonographic measurement of cervical dimensions between 24 and 34 weeks' gestation in pregnant Thai women.

OBJECTIVE: To assess serial changes of cervical dimensions in pregnant Thai women between 24 and 34 weeks' gestation by translabial sonography. METHODS: A longitudinal study of cervical dimensions obtained by translabial sonography at 24, 28, 30, 32, and 34 weeks' gestation in 144 women was conducted. The gestational age at labor was recorded and women were defined as having preterm labor or term labor according to whether there was onset of true labor pain before or after 37 completed weeks, respectively. Cervical changes over time were analyzed by repeated ANOVA. The associations between cervical dimensions and gestational age, parity and prepregnancy body mass index were calculated by multiple linear regression analysis. RESULTS: Cervical length decreased whereas cervical width increased as gestational age advanced. Cervical length and width in women with term labor, but only cervical length in women with preterm labor, changed significantly throughout the period of 24-34 weeks' gestation (P < 0.01). The cervix was significantly longer in parous women and in women with a body mass index of more than 26 kg/m2, but was shorter in women of advanced gestational age. The cervix was significantly wider in parous women and in those of advanced gestational age. Weekly crude rate, adjusted for parity and prepregnancy body mass index, of both cervical length shortening and cervical width widening was 0.4 mm in women with term labor. Women with preterm labor had cervical shortening of 0.5 mm per week. CONCLUSIONS: Gestational age, parity and prepregnancy body mass index are significantly associated with the dynamic changes of cervical length and width in Thai women. These factors should be considered when assessing normal values of cervical dimensions and for predicting the risk of preterm delivery.     

Sonography of fetal choroid plexus cysts: detection depends on cyst size and gestational age.

OBJECTIVE: To establish diagnostic criteria for the diagnosis of fetal choroid plexus cysts across gestation. METHODS: Prenatal sonographic images of 166 fetuses without choroid plexus cysts were prospectively collected from 13 weeks to term. Texture characteristics of the choroid plexus regions were analyzed to quantify changes as a function of gestational age. A set of 20 fetal sonographic images with choroid plexus cysts were used to create cyst prototypes (1.5-2.5 mm), which were randomly embedded into normal choroid plexus images from varying gestational ages. A test set of 544 images was created, which included 408 images with choroid plexus cysts and 136 images without choroid plexus cysts. Four observers following a blinded study design evaluated the presence of choroid plexus cysts in the images. The influence of cyst size and gestational age on the detection of cysts was measured with receiver operating characteristic analysis and analysis of variance. Observer agreement was characterized by agreement kappa statistics. RESULTS: Texture analysis indicated greater echo texture heterogeneity at earlier gestational ages. The receiver operating characteristic analysis showed a corresponding decrease in diagnostic accuracy for cyst detection at earlier gestational ages. The cyst detection threshold (area under the receiver operating characteristic curve, 0.8) was 2.4 mm (SE, 0.2 mm) for 13 to 21 weeks' gestation and decreased to 1.9 mm (SE, 0.17 mm) for 22 to 38 weeks' gestation. Average interobserver and intraobserver kappa statistics were 0.37 and 0.53, respectively. CONCLUSIONS: Because of the changing echo texture of the choroid plexus through gestation, choroid plexus cysts must be at least 2.5 mm in diameter for confident diagnosis before 22 weeks' gestation and at least 2 mm after 22 weeks.     

Sonographic identification and measurement of the epiphyseal ossification centers as markers of fetal gestational age

PURPOSE: This study was conducted to verify the predictive value of epiphyseal ossification center measurements in estimating gestational age. METHODS: Women with singleton pregnancies of 30-40 weeks gestation (n = 377) were enrolled in this prospective study. The distal femoral, proximal tibial, and proximal humeral ossification centers were identified and measured. A nomogram of fetal bone development was created using the sum of the three diameters. RESULTS: Gestational age correlated well with the diameters of the distal femoral and the proximal tibial epiphyseal ossification centers but even better with the sum of the three ossification centers. Positive predictive values of the fetus having gestational age of at least 37 weeks when the sum of the three centers was 7, 11, and 13 mm were 82%, 94%, and 100%, respectively. A nomogram was created using the sum of the ossification centers for 30-40 weeks' gestational age. CONCLUSIONS: Ultrasonographic visualization of the epiphyses ossification centers may be a useful marker of fetal gestational age.     

Isolated hyperechogenic foci in the fetal thalamus in early pregnancy.

OBJECTIVE: To describe the sonographic features and outcome of fetuses with isolated hyperechogenic foci in the thalamic region. METHODS: A detailed sonographic survey was performed in 46,244 consecutive pregnancies. Both low- and high-risk pregnancies were included. Transvaginal examinations were performed at 14-16 weeks' gestation, while transabdominal examinations were performed after 18 weeks' gestation. RESULTS: Isolated hyperechogenic foci in the thalamic region were observed in seven fetuses. All cases were diagnosed at 14-16 weeks' gestation. Six fetuses had one hyperechogenic focus, and one fetus had two foci. The size of these foci ranged from 2-4 mm. A serologic work-up was negative in all these fetuses and their karyotype was normal. The hyperechogenic foci disappeared in mid-pregnancy in all cases, and fetuses were normal at delivery and on follow up to the age of 9 years. CONCLUSIONS: Isolated hyperechogenic foci in the thalamic region in early pregnancy are probably benign in nature.     

The development of the fetal sternum: a cross-sectional sonographic study.

OBJECTIVE: To assess the relationship between gestational age and sonographic appearance of the various sternal components and establish growth during human gestation. DESIGN: A prospective cross-sectional study. METHODS: The study was performed on 252 consecutive normal singleton pregnancies from 19 weeks of gestation until term, using transabdominal high-resolution ultrasound techniques. The sternal length, as well as the number of ossification centers at each gestational age, were recorded. RESULTS: The first occasion at which a fetal human sternum could be visualized with two to three ossification centers was at 19 weeks' gestational age. The fifth ossification center was first visualized at 29 weeks' gestation. The mean +/- SE of sternal length varied from 15 +/- 0.98 mm (95% confidence interval (CI) 12.79-17.21) at 19-20 weeks, to 36.50 +/- 0.29 mm (95% CI 35.58-37.42) at 37-38 weeks' gestation. Sternal length as a function of gestational age was expressed by the regression equation: sternal length (mm) = -11.06 + 1.39 x gestational age (weeks). The correlation coefficient, r = 0.924 for sternal length, was found to be highly statistically significant (p < 0.0001). CONCLUSIONS: The presented data offer normative measurements of the fetal sternum which may be helpful in the prenatal diagnosis of congenital syndromes that include, among other manifestations, abnormalities of sternal development.     

The fetal mandible measurement: an objective determination of fetal jaw size.

The sonographic diagnosis of micrognathia has been limited by the lack of an objective measurement of the fetal mandible. A cross-sectional study of 134 normal patients of known gestational age between 14 and 39 weeks' gestation was performed. Models to predict mandible length based on gestational age, biparietal diameter, head circumference or femur length were derived by least squares regression analysis. The 95% prediction limits were also derived. Utilization of these curves generated from a normal population should allow for a more sensitive and reproducible method to diagnose micrognathia in the fetus.     

Fetal aortic arch measurements between 14 and 38 weeks' gestation: in-utero ultrasonographic study.

OBJECTIVE: To establish in-utero reference ranges for fetal transverse aortic arch diameter (TAD) and distal aortic isthmus diameter (DAID) using high-resolution ultrasound techniques. DESIGN: A prospective, cross-sectional study was performed on 125 normal singleton pregnancies between 14 and 38 weeks' gestation. Transverse and diameter and DAID were measured by transvaginal ultrasonography until 17 weeks' gestation, and by abdominal ultrasound between 18 and 38 weeks' gestation. RESULTS: Transverse arch diameter as a function of gestational age was expressed by the regression equation TAD = -1.17 + 0.169 X GA, and DAID = -1.39 + 0.189 X GA; TAD and DAID are transverse aortic and distal aortic isthmus diameters expressed in millimeters and GA is gestational age in weeks. The correlation r = 0.924 and 0.938 was found to be highly statistically significant (P < 0.001) for TAD and DAID. The normal mean of TAD and DAID per week and the 95% prediction limits were also defined. CONCLUSIONS: The normative data established by us may be helpful in the prenatal diagnosis of congenital heart defects, including abnormal growth of the aortic arch.     

Fetal lumbar spine volumetry by three-dimensional ultrasound.

OBJECTIVES: To evaluate three-dimensional sonographic volume measurements of the thoracolumbar spine from 16 to 25 weeks of gestation in the normally developing fetus. DESIGN: Prospective cross-sectional study. SUBJECTS: The study included 103 women between 16 and 25 weeks of gestation. They were enrolled at the time of their anomaly scan. None of the pregnancies was associated with structural anomalies and in each case fetal size was deemed appropriate for gestational age. METHODS: Three-dimensional volume calculation of the 1st and 5th lumbar vertebral body, the 12th thoracic vertebral body and the whole lumbar spine was performed, using the perpendicular frontal, sagittal and transverse planes. The lumbar spine length was determined. RESULTS: A statistically significant increase in all measurements was found with advancing gestational age. CONCLUSIONS: Three-dimensional ultrasonography allows volume calculation of the fetal spine. Our study provides preliminary data about volume changes in the developing fetal spine between 16 and 25 weeks' gestation.     

Molecular prenatal diagnosis in 2 pregnancies at risk for spondyloepiphyseal dysplasia congenita

BACKGROUND: Spondyloepiphyseal dysplasia congenita (SEDC) is an autosomal dominant skeletal dysplasia characterized by short stature, abnormal epiphyses, and flattened vertebral bodies. Secondary prevention of SEDC can be achieved by prenatal diagnosis. Reports of antenatally-diagnosed SEDC fetuses have been very rare and molecular prenatal diagnosis even rarer. We previously reported a familial G504S mutation in the type II collagen (COL2A1) gene resulting in SEDC. In this study, molecular prenatal diagnosis was performed to 2 couples in this family with pregnancies at risk for SEDC. METHODS: Amniotic fluid was sampled by amniocentesis under ultrasound guidance at 19+3 and 18+6 weeks' gestation, respectively. Karyotype and molecular genetic analysis were performed on cultured amniotic fluid cells. Maternal cell contamination was excluded by short tandem repeat (STR) analysis. Direct DNA sequencing and DHPLC were conducted to detect the potential mutation in exon 23 of COL2A1 gene. Both women underwent serial sonograms because they insisted that the molecular diagnosis should be confirmed by another method, although they had been informed that mutation analysis is predictive of the disease. RESULTS: Karyotype of both fetuses was normal and molecular genetic analysis revealed that fetus 1 carried a G504S mutation in exon 23, while fetus 2 was normal. In case 1, femur length of the fetus was markedly below the 5th centile at 23 weeks' gestation, which confirms the accuracy of molecular diagnosis. A medical termination was carried out at 27+5 weeks' gestation and a male fetus with a relatively large head and short limbs was delivered. The fetal radiograph demonstrated a number of features, including generalised platyspondyly, absent ossification of the vertebral bodies in the cervical region and significant shortening of the long bones. The diagnosis of SEDC was thus confirmed clinically. Ultrasound monitoring of fetus 2 showed that its femur length was normal for gestational age at repeated scans, which was consistent with the molecular diagnosis. CONCLUSIONS: Molecular analysis allows early and accurate prenatal diagnosis for SEDC once mutation is known in a family. However, considering the poor genotype/phenotype correlation in many cases of SEDC, the combination of ultrasound as well as molecular genetic approach might be needed.