应用孕妇外周血胎儿有核红细胞数量及胎儿脐动脉血流变化预测胎儿慢性缺氧

Predicting chronic fetal distress by counting fetal nucleated red blood cells in maternal peripheral blood and observing hemodynamics of umbilical arteries

目的探讨母血中胎儿有核红细胞(fetal nucleated red blood cells,FNRBC)数量及胎儿脐动脉血流改变与胎儿慢性缺氧的关系。方法对78例孕妇(正常妊娠组30例、胎儿急性缺氧组18例、胎儿慢性缺氧组30例)的外周血分别进行单密度梯度离心、FNRBC计数;同时行彩色多普勒超声检测胎儿脐动脉血流搏动指数(pulsatility indexes,PI)、阻力指数(resistance indexes,RI)及收缩期最大血流速度与舒张末期血流速度的比值(systolic/diastolic,S/D);比较单法检测及二法联检的灵敏度、特异度及诊断正确率等。并通过病理证实胎盘变化。结果胎儿慢性缺氧组、急性缺氧组、正常妊娠组孕妇外周血中FNRBC计数分别为(15.42±4.11)、(6.92±2.17)、(5.95±1.76)个/6ml,慢性缺氧组FNRBC计数明显高于其他2组(P<0.05),而后两组间比较无显著性差异(P>0.05)。慢性缺氧组脐血流S/D、PI、RI值分别为(3.27±0.66)、(1.12±0.15)和(0.71±0.07),均显著高于正常妊娠组的(2.16±0.25)、(0.69±0.10)和(0.55±0.06)(P<0.05)。慢性缺氧组孕妇外周血中FNRBC计数与脐动脉血流参数S/D及PI值呈正相关(r=0.815、r=0.587,P<0.05),而正常妊娠组孕妇外周血中FNRBC计数与脐动脉血流各参数之间均无相关性。与单独检测相比,2种方法联合检测预测胎儿慢性缺氧的灵敏度、诊断正确率最高。结论胎儿慢性缺氧时母血中FNRBC计数、脐动脉S/D、PI值升高,二者呈正相关;二法联检能提高预测胎儿慢性缺氧的灵敏度及诊断正确率。

Objective To explore the relationship of fetal nucleated red blood cell counting and hemodynamics of umbilical arteries with chronic fetal distress, and provide experimental support to handle this clinic problem timely and rightly. Methods A total of 78 pregnant women, including 30 normal pregnant, 18 acute fetal distress groups and 30 chronic fetal distress groups were enrolled in this study after the informed consent was signed and the protocol was approved by the Ethics Committee of our hospital. Fetal nucleated red blood cells were isolated from maternal peripheral blood with single density gradient centrifugation and then counted. Color Doppler blood flow visualize technology was used to defect the pulsatility indexes （PI） , resistance indexes （RI） and systolic/diastolic （S/D） ratio of fetal umbilical arteries. The results were compared among different groups. The sensitivity, speciality, diagnostic accuracy of the 2 methods, cell counting and uhrasonography, alone or combined together, were evaluated. Placenta change was verified by pathological method. Results The mean number of fetal nucleated red blood cells in maternal peripheral blood was 15.42 ± 4.11, 6.92 ± 2. 17, and 5.95 ± 1.76 cells/6 ml respectively in chronic fetal distress group, acute fetal distress group and normal pregnant group. The cell numbers of chronic fetal distress group was markedly higher than the other 2 groups （P 〈 0.05 ）. No difference was found between the acute fetal distress group and the normal control group （P 〉0.05）. In the chronic fetal distress group, umbilical artery S/D, PI and RI value was 3.27 ±0.66, 1.12 ± 0.15 and 0.71 ± 0.07 respectively, which were higher than those of normal pregnant group （ 2. 16 ±0.25,0. 69 ±0. 10 and 0.55 ± 0. 06 respectively, P 〈 0.05 ）. The counting of fetal nucleated red blood cells in chronic fetal distress group had a positive linear correlation with its umbilical artery S/D and PI values, but no such correlation was found in the normal pregnant group. The sensitivity and diagnostic accuracy of combined 2 methods was higher than either method alone. The results of the 2 methods were verified by pathological observation on the placenta. Conclusion The numbers of fetal nucleated red blood cells in maternal blood and umbilical artery S/D are increased markedly in the fetal chronic distress groups. So the 2 values can be used as the markers of chronic fetal distress. Combining the 2 methods together will improve the sensitivity and diagnostic accuracy to predict and diagnose chronic fetal distress.