Banu A A
Department of Gynecology and Obstetrics, Faculty of Medicine, Kyushu University Fukuoka, Japan.
Fukuoka Igaku Zasshi. 1998 May;89(5):133-44.
To clarify the usefulness of Doppler velocimetry in high-risk fetuses, i.e. with intrauterine growth retardation (IUGR) or with fetal distress, nomograms of the age-related changes in resistance and pulsatility indices in the fetal umbilical and middle cerebral arteries were made, and the best cut-off values for each parameter were determined. Included were 505 and 684 fetuses as the control and subject groups, respectively, between 22 and 41 weeks' gestation. Using the color-coded pulsed Doppler method, the resistance index in the umbilical and middle cerebral artery (RIUA, RIMCA), the pulsatility index in both these arteries (PIUA, PIMCA), and the RI and PI ratios between these arteries (RIUA/MCA, PIUA/MCA) were measured. In normal fetuses, RIUA and PIUA showed a gradual decrease with advance in gestational age. RIMCA and PIMCA showed a parabolic fashion with a peak around 30-31 weeks' gestation. RIUA/MCA and PIUA/MCA ratios decreased until 30-31 weeks' gestation and then increased to term. Analyses with receiver-operating-characteristic (ROC) curves revealed that PIUA is the most appropriate parameter in identifying IUGR under the cut-off point of 1.5 S.D., with a sensitivity, specificity, positive and negative predictive value, and accuracy of 60.6%, 93.3%, 75.2%, 87.6%, and 85.0%, respectively. As for fetal distress, the PIUA/MCA ratio was the most efficacious parameter under the cut-off point of 2.0 S.D., with a sensitivity, specificity, positive and negative predictive value, and accuracy of 67.3%, 97.4%, 72.9%, 96.7% and 94.6%, respectively. The findings obtained indicate that the measurement of PI value in the umbilical artery is enough to detect IUGR per se, probably due to the reflection of the decrease in the placental vascular bed, and that the ratio of indices between the umbilical artery and middle cerebral artery is more accurate than independent evaluations in identifying fetuses developing fetal distress, reflecting a brain sparing effect as well as fetoplacental insufficiency.
为阐明多普勒测速法在高危胎儿（即宫内生长受限[IUGR]或胎儿窘迫）中的应用价值，绘制了胎儿脐动脉和大脑中动脉阻力及搏动指数随孕周变化的列线图，并确定了每个参数的最佳截断值。纳入了妊娠22至41周的505例和684例胎儿，分别作为对照组和研究组。采用彩色编码脉冲多普勒法，测量脐动脉和大脑中动脉的阻力指数（RIUA、RIMCA）、这两条动脉的搏动指数（PIUA、PIMCA）以及这两条动脉之间的RI和PI比值（RIUA/MCA、PIUA/MCA）。在正常胎儿中，RIUA和PIUA随孕周增加逐渐降低。RIMCA和PIMCA呈抛物线形，在妊娠30 - 31周左右达到峰值。RIUA/MCA和PIUA/MCA比值在妊娠30 - 31周前降低，然后足月时升高。通过受试者工作特征（ROC）曲线分析显示，PIUA是在标准差1.5的截断点下识别IUGR的最合适参数，其敏感性、特异性、阳性和阴性预测值以及准确性分别为60.6%、93.3%、75.2%、87.6%和85.0%。至于胎儿窘迫，PIUA/MCA比值是在标准差2.0的截断点下最有效的参数，其敏感性、特异性、阳性和阴性预测值以及准确性分别为67.3%、97.4%、72.9%、96.7%和94.6%。所得结果表明，测量脐动脉的PI值本身足以检测IUGR，这可能是由于胎盘血管床减少的反映，并且脐动脉与大脑中动脉指数比值在识别发生胎儿窘迫的胎儿方面比独立评估更准确，反映了脑保护效应以及胎儿 - 胎盘功能不全。
