Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Washington University School of Medicine, 4990 Children's Pl, Suite 1130, St Louis, MO 63110, USA.
J Ultrasound Med. 2009 Dec;28(12):1603-10. doi: 10.7863/jum.2009.28.12.1603.
The purpose of this study was to compare the screening efficiency of the umbilical artery systolic to diastolic ratio (S/D), pulsatility index (PI), and absent end-diastolic flow (AEDF) for adverse pregnancy outcomes and placental abnormalities in small for gestational age (SGA) fetuses.
We conducted a retrospective cohort study of Doppler examinations of 161 nonanomalous SGA fetuses. The reliability of the S/D and PI were quantified by intraclass correlation coefficients. The association of the S/D, PI, and AEDF with adverse outcomes and placental abnormalities was compared by the chi(2) test.
There was a simple association of Doppler results with adverse outcomes, which was mitigated when controlled for gestational age. For all measures of adverse outcomes, the specificity of abnormal Doppler results exceeded the sensitivity, and the negative predictive value was greater than the positive predictive value. Comparing the S/D with the PI, there was no significant difference in the sensitivity; however, the specificity of the PI was at least 90% and exceeded that of the S/D for all outcomes. The intraclass correlation coefficients of the S/D and PI were similar, indicating no difference in reliability. Placental abnormalities were significantly more common in cases with abnormal Doppler values (positive predictive value, 94%) with no overlap in the types of placental lesions in most cases.
As an initial screen for adverse outcomes in SGA fetuses, the umbilical artery Doppler S/D, PI, and AEDF were imprecise. However, these measures were all strongly and similarly predictive of placental abnormalities, especially lesions of maternal underperfusion and fetal vascular obstruction.
本研究旨在比较脐动脉收缩期与舒张期比值（S/D）、搏动指数（PI）和无舒张末期血流（AEDF）在预测生长受限（SGA）胎儿不良妊娠结局和胎盘异常方面的筛查效率。
我们对 161 例非畸形 SGA 胎儿进行了多普勒超声检查的回顾性队列研究。采用组内相关系数来量化 S/D 和 PI 的可靠性。通过卡方检验比较 S/D、PI 和 AEDF 与不良结局和胎盘异常的相关性。
多普勒结果与不良结局存在简单关联，但在控制胎龄后得到缓解。对于所有不良结局的评估指标，异常多普勒结果的特异性均超过了敏感性，阴性预测值大于阳性预测值。与 S/D 相比，PI 的敏感性没有显著差异；然而，PI 的特异性对于所有结局均至少为 90%，超过了 S/D。S/D 和 PI 的组内相关系数相似，表明可靠性无差异。胎盘异常在异常多普勒值的情况下更为常见（阳性预测值为 94%），且大多数情况下胎盘病变类型没有重叠。
作为 SGA 胎儿不良结局的初始筛查，脐动脉多普勒 S/D、PI 和 AEDF 不精确。然而，这些方法都强烈且相似地预测了胎盘异常，尤其是母体灌注不足和胎儿血管阻塞的病变。
