Prenatal Diagnosis Of Congenital Anomalies

在美国，先天畸形是继早产之后导致围产儿死亡的第二大原因。成像技术的进步使超声能够在宫内检测许多解剖缺陷。该项目的目标是提高胎儿疾病和先天畸形的诊断和治疗水平。围产期研究处发起了一系列项目，以改进先天性异常的检测，并使用三维超声评估胎儿的生长和发育。由于先天性心脏病是先天畸形胎儿死亡的主要原因，已投入大量精力开发技术，以改进先天心脏病的产前诊断。今年的调查结果包括： 1.应用四维超声对心脏大血管和静脉回流的数字模型：围产期研究分部的研究人员描述了一种使用具有时空图像相关(STIC)和反转模式或B-Flow成像的四维超声重建大血管和静脉回流到心脏的技术。使用这些技术的心血管结构的四维重建允许数字管型的可视化。类似于在尸检中可以获得的心血管系统的硅橡胶模型。可以清楚地观察流出道之间的空间关系、大动脉与脑室的连接以及静脉系统和心房之间的连接。应用该技术诊断主动脉缩窄、大动脉转位、右室双出口、肺动脉狭窄、肺闭锁及下腔静脉断流伴奇静脉或半奇静脉断裂。除了改善流出道和静脉回流到心脏的可视化，与二维超声相比，将倒置模式应用于四腔切面的容量数据集可以更清晰地描绘心脏轮廓、房室瓣和室间隔缺陷。对尿路梗阻患者的胃、脑室系统、扩张的输尿管和肾盆等充液结构的重建也采用了倒置模式的三维超声。 2.三维超声对正常胎儿个体化生长的评估：本研究引入了一种新的可由三维超声评估的软组织参数--手臂体积分数(AVOL)，用于纵向评估胎儿的生长发育。在Rossavik模型的基础上，利用AVOL、臂围(ARMC)和骨干长度(HDL3)制定了个体化生长标准。对22例胎儿进行了二维和三维超声前瞻性研究。根据妊娠28周前生长曲线的线性斜率建立中期妊娠模型，并预测每个参数的正常晚期妊娠轨迹。Rossavik函数非常好地拟合了所有参数轨迹(R(2)=95.7%-99.4%)，晚期妊娠高密度脂蛋白、ARMC和AVOL的测量值与预测值的平均百分比偏差分别为-0.1%+/-2.9%、0.5%+/-4.6%和0.4%+/-8.5%。这项研究表明，可以通过测量胎儿手臂的体积来进行个性化的生长评估，并且可以准确地预测晚期妊娠胎儿手臂的生长。AVOL可以及早发现并改进对患有生长障碍的胎儿软组织异常的监测。 3.羊水“淤泥”在早产和胎膜完整患者中的患病率和临床意义：该分支机构检查了宫颈管腔附近特殊物质致密聚集体的临床意义？羊水？淤泥？--这是一种在早产和胎膜完整的患者中经常观察到的超声表现。羊水、淤泥的流行情况？对84例胎膜完整的早产患者和298例正常足月妊娠的孕妇进行了检测。比较两组间羊膜腔微生物侵袭率(MIAC)、组织学绒毛膜羊膜炎、检查至分娩间隔时间、新生儿重症监护病房(NICU)住院时间、新生儿综合发病率、围产儿死亡率及48小时、7天、35周和32周内分娩情况。无并发症足月妊娠组羊水“淤泥”发生率为1%(3/298)，早产组羊水“淤泥”发生率为22.6%(19/84)。羊水“淤泥”患者自然早产率较高。有羊水的病人？有淤泥？羊水培养阳性率[33.3%(6/18)比2.5%(1/40)，P=0.003]和组织学绒毛膜羊膜炎阳性率[77.8%(14/18)比19%(11/58)，P&lt；0.001]，新生儿进入NICU[64.3%(9/14)比12.9%(8/62)，P&lt；死亡率分别为36.8%(7/19)和4.6%(3/65)，P=0.001。

Congenital anomalies are the second leading cause of perinatal mortality in the United States after premature birth. Advances in imaging techniques have allowed the in utero detection of many anatomical defects with ultrasound. The goal of this project is to improve the diagnosis and treatment of fetal disease and congenital anomalies. The Perinatology Research Branch has initiated a series of projects to improve the detection of congenital anomalies and assess fetal growth and development with the use of three-dimensional ultrasound. A substantial effort has been invested in the development of techniques to improve the prenatal diagnosis of congenital heart disease since this is the leading cause of death among fetuses with congenital anomalies. The findings of this year include the following: 1. Digital casts of the great vessels and venous return to the heart using four-dimensional ultrasound: Investigators at the Perinatology Research Branch described a technique for reconstruction of the great vessels and venous return to the heart using four-dimensional ultrasonography with spatiotemporal image correlation (STIC), and inversion mode or B-flow imaging. Four-dimensional reconstruction of cardiovascular structures using these techniques allowed the visualization of ?digital casts? similar to the silicone rubber casts of the cardiovascular system that can be obtained during postmortem examinations. Spatial relationships between the outflow tracts, the connections of the great arteries to the ventricular chambers, and the connections between the venous system and atrial chambers could be clearly observed. The technique was applied to the diagnosis of coarctation of the aorta, transposition of the great arteries, double outlet right ventricle, pulmonary stenosis, pulmonary atresia and interruption of the inferior vena cava with azygous or hemiazygous continuation. In addition to improved visualization of the outflow tracts and venous return to the heart, the application of inversion mode to volume datasets of the four-chamber view allowed sharper delineation of the cardiac contours, atrioventricular valves and ventricular septal defects when compared to two-dimensional ultrasound. Three-dimensional ultrasound with inversion mode was also used for the reconstruction of fluid-filled structures such as the stomach, the ventricular system of the brain, and dilated ureters and renal pelvis in cases of urinary tract obstruction. 2. Individualized growth assessment of normal fetuses using three-dimensional ultrasound: This study introduced a new soft tissue parameter that can be evaluated by three-dimensional ultrasound -fractional arm volume (AVol) - for longitudinal assessment of fetal growth. Individualized growth standards based on Rossavik models were developed using AVol, mid arm circumference (ArmC), and humeral diaphysis length (HDL). Twenty-two fetuses were prospectively studied by two- and three-dimensional ultrasound. Second-trimester models were constructed from the linear slopes of growth curves before 28 weeks of gestation and normal third-trimester trajectories were predicted for each parameter. The Rossavik functions fit all parameter trajectories extremely well (R(2)=95.7%-99.4%) and the mean percent deviations between observed and predicted third-trimester HDL, ArmC, and AVol measurements were -0.1% +/- 2.9%, 0.5% +/- 4.6%, and 0.4% +/- 8.5%, respectively. The study demonstrated that individualized growth assessment can be performed by volumetric measurements of the fetal arm and that third trimester fetal arm growth can be accurately predicted. AVol may allow early detection and improved monitoring of soft tissue abnormalities that occur in fetuses with growth disorders. 3. Prevalence and clinical significance of amniotic fluid 'sludge' in patients with preterm labor and intact membranes: The Branch examined the clinical significance of dense aggregates of particular matter in the proximity of the cervical canal ? amniotic fluid ?sludge? - an ultrasound finding that is frequently observed in patients with preterm labor and intact membranes. The prevalence of amniotic fluid ?sludge? was determined in 84 patients with preterm labor and intact membranes and 298 uncomplicated pregnancies at term. The frequency of microbial invasion of the amniotic cavity (MIAC), histological chorioamnionitis, examination-to-delivery interval, admission to the neonatal intensive care unit (NICU), composite neonatal morbidity, perinatal death, and delivery within 48 h, 7 days, and < 35 weeks and < 32 weeks were compared between the two groups. The prevalence of amniotic fluid 'sludge' was 1% (3/298) in patients with uncomplicated term pregnancies and 22.6% (19/84) in those with preterm labor and intact membranes. The rate of spontaneous preterm delivery was higher in patients with amniotic fluid 'sludge'. Patients with amniotic fluid ?sludge? had a higher frequency of positive amniotic fluid cultures [33.3% (6/18) vs. 2.5% (1/40), P = 0.003] and histological chorioamnionitis [77.8% (14/18) vs. 19% (11/58), P < 0.001] and, in addition, their neonates were admitted to the NICU [64.3% (9/14) vs. 12.9% (8/62), P < 0.01] or died more often [36.8% (7/19) vs. 4.6% (3/65), P = 0.001] than those without amniotic fluid 'sludge'.