Mitra A G, Laurent S L, Moore J E, Blanchard G F, Chescheir N C
Department of Obstetrics, Carolinas Medical Center, USA.
Am J Obstet Gynecol. 1996 Jul;175(1):41-4. doi: 10.1016/s0002-9378(96)70248-x.
Our purpose was to determine whether transvaginal Doppler auscultation is more sensitive than transabdominal auscultation for the detection of fetal heart rate in the first trimester of pregnancy.
In a prospective study 141 patients between 6 weeks and 11 weeks 6 days of gestation underwent both transvaginal and transabdominal Doppler evaluation by use of continuous-wave Doppler instruments for detection of fetal heart rate. Transvaginal ultrasonography was used as the gold standard to establish fetal cardiac activity and to help assign gestational age. The two methods of auscultation were compared for accuracy in different gestational age ranges. Sensitivities and specificities were calculated, and associations were investigated with chi 2 analysis. The direction of disagreement between modalities was tested with the McNemar chi 2 test.
Transvaginal auscultation outperformed transabdominal auscultation in every gestational age range. Transvaginal Doppler auscultation performed significantly better than transabdominal Doppler auscultation at 8 weeks to 8 weeks 6 days (p < or = 0.004) and 9 weeks to 9 weeks 6 days (p < or = 0.006). In pregnancies with cardiac activity, fetal heart rate can be successfully detected transvaginally in 60.5% of pregnancies at 8 weeks to 8 weeks 6 days and in 87.5% of pregnancies at 9 weeks to 9 weeks 6 days of gestation. This compares with successful transabdominal detection rates of 22.9% and 56% at 8 and 9 weeks, respectively. As gestational age advances both methods became increasingly sensitive for the detection of fetal heart rate. The earliest fetal heart rate detected transvaginally was at 6 weeks 0 days of gestation compared with 7 weeks 0 days transabdominally. The transvaginal Doppler method was also more successful in detecting the fetal heart rate in women with a retroverted uterus (p < or = 0.01).
By use of continuous-wave Doppler instrumentation, transvaginal auscultation is significantly better than transabdominal auscultation in detecting fetal heart rate between 8 weeks to 8 weeks 6 days and 9 weeks to 9 weeks 6 days of gestation. Use of transvaginal auscultation has potential in the evaluation of first-trimester fetal cardiac activity.
我们的目的是确定经阴道多普勒听诊在妊娠早期检测胎儿心率方面是否比经腹听诊更敏感。
在一项前瞻性研究中，141例妊娠6周零天至11周6天的患者接受了经阴道和经腹多普勒评估，使用连续波多普勒仪器检测胎儿心率。经阴道超声检查被用作确定胎儿心脏活动和帮助确定孕周的金标准。比较了两种听诊方法在不同孕周范围内的准确性。计算敏感性和特异性，并采用卡方分析研究相关性。用McNemar卡方检验检测两种方法之间不一致的方向。
在每个孕周范围内，经阴道听诊均优于经腹听诊。经阴道多普勒听诊在8周零天至8周6天（p≤0.004）和9周零天至9周6天（p≤0.006）时明显优于经腹多普勒听诊。在有心脏活动的妊娠中，在妊娠8周零天至8周6天，经阴道成功检测到胎儿心率的妊娠占60.5%；在妊娠9周零天至9周6天，这一比例为87.5%。相比之下，经腹在8周和9周时成功检测率分别为22.9%和56%。随着孕周增加，两种方法对胎儿心率的检测都变得越来越敏感。经阴道最早检测到胎儿心率是在妊娠6周零天，而经腹是在7周零天。经阴道多普勒方法在检测子宫后倾妇女的胎儿心率方面也更成功（p≤0.01）。
使用连续波多普勒仪器时，经阴道听诊在妊娠8周零天至8周6天和9周零天至9周6天检测胎儿心率方面明显优于经腹听诊。经阴道听诊在评估妊娠早期胎儿心脏活动方面具有潜力。
