Firpo C, Hoffman J I, Silverman N H
University of California-San Francisco 94143, USA.
Am J Cardiol. 2001 Mar 1;87(5):594-600. doi: 10.1016/s0002-9149(00)01437-5.
To evaluate whether fetal cardiac measurements can be made in the second trimester, we examined a cohort of normal pregnancies between 12 and 18 weeks' gestation using state-of-the-art ultrasound equipment. We examined this population longitudinally at intervals of 2 weeks, as well as at 32 weeks' gestation. From the 4-chamber view we measured the ventricular and atrial cavity dimensions, the thickness of the ventricular walls and septum at end-diastole, and the annulus dimensions of the mitral and tricuspid valves. Using a variety of views we also measured the long and cross-sectional diameters of the atria, the aorta, the pulmonary artery and its main left and right branches, the ductus arteriosus, and the superior and inferior vena cavae. To test the frequency with which measurements could be made, we divided them into measurements that were clear and easy to define (statistically good), to those that were unclear (statistically bad), or those that were not measured at all (none). Data were then analyzed by regression analysis, analysis of variance, and covariance. The frequency of reliable measurements varied inversely with gestational age. The inflection point for measurements was approximately at 16 weeks. Data from this longitudinal study were evaluated against those obtained from our previous study. Because no statistical differences were found in measurements between these studies where they overlapped, the data were pooled into 1 large group and the mean and SEEs calculated for all variables. Our study demonstrates that with current transabdominal imaging, fetal cardiac measurements can be made reliably in normal fetuses from 16 weeks' gestation onward. The frequency of obtaining data in younger normal fetuses suggests it is unlikely that reliable observations can be made routinely in abnormal fetuses < 16 weeks old, although this might be possible in individual fetuses.
为评估孕中期能否进行胎儿心脏测量，我们使用最先进的超声设备，对12至18周妊娠的正常孕妇队列进行了检查。我们每隔2周对该人群进行纵向检查，并在孕32周时进行检查。从四腔心切面，我们测量了心室和心房腔的尺寸、舒张末期心室壁和室间隔的厚度，以及二尖瓣和三尖瓣环的尺寸。我们还使用多种切面测量了心房、主动脉、肺动脉及其主要左右分支、动脉导管以及上、下腔静脉的长径和横径。为测试测量的频率，我们将测量结果分为清晰易定义的测量值（统计学上良好）、不清晰的测量值（统计学上差）或根本未测量的测量值（无）。然后通过回归分析、方差分析和协方差分析对数据进行分析。可靠测量的频率与胎龄成反比。测量的转折点约在16周。将这项纵向研究的数据与我们之前研究获得的数据进行了评估。由于在这些研究重叠的测量中未发现统计学差异，因此将数据汇总为一个大组，并计算所有变量的均值和标准误。我们的研究表明，使用当前的经腹成像技术，从孕16周起可以在正常胎儿中可靠地进行胎儿心脏测量。在较年轻的正常胎儿中获取数据的频率表明，对于小于孕16周的异常胎儿，不太可能常规进行可靠的观察，尽管个别胎儿可能可行。
