彩色多谱勒超声在诊断胎儿生长受限(FGR)中的应用

目的评价生长受限胎儿大脑中动脉和脐动脉血流多谱勒特点、它们的相互关系以及新生儿预后。方法检测65例生长受限胎儿剖宫产前大脑中动脉和脐动脉血流多谱勒波形中搏动指数。结果显示有如下3种特点：1期有39例，UAPI〈MCAPI（没有脑保护效应）；2期有23例，UAPI〉MCAPI（有脑保护效应）；3期3例，随舒张未期血流减少搏动指数升高或出现舒张末期反流，这种情况诊断为脑保护效应失代偿。分娩时检测脐带血气数据，并进行两两比较。结果每一时期分娩时孕周和体重有显着性差异（P〈0．05）。各个时期新生儿平均体重显着低于标准体重（国际标准），这提示生长受限。3期PH期和剩余碱明显不同于其它两期（P〈0．05）。结论脑保护效应失代偿生长受限胎儿分娩提前，并且有严重生长受限和轻度代谢性酸中毒。MCAPI从低到高的变化以及UAPI进行性增加可预示胎儿严重生长受限。

Characterization of fetal growth restriction with breakdown of the brain-sparing effect diagnosed by spectral Doppler

Objective: To characterize serial findings of the middle cerebral artery(MCA) and umbilical artery(UA) flow pattern,their relationship to each other,and neonatal outcomes in growth-restricted fetuses.Methods: Serial pulsatility indices(PIs) from MCA and UA Doppler waveforms were measured in 65 growth-restricted fetuses until Cesarean delivery.We found three patterns,as follows: phase 1(n=39),UA PI MCA PI(brain-sparing effect);phase 3(n=3),both PIs elevated with the absence of end-diastolic flow or presence of reverse end-diastolic flow,which was designated as the 'breakdown of the brain-sparing effect'.Umbilical cord blood gas data at delivery were compared between each group.Results:Age at delivery and body weights were significantly different for each phase(P<0.05).The mean body weights in all phases were significantly decreased from International standard body weights,indicating growth restriction.The phase 3 pH and base excess were significantly different from those of the other two phases(P<0.05).Conclusion:Growth-restricted fetuses which suffered from the state of breakdown of the brain-sparing effect were delivered early with severe growth restriction and mild metabolic acidosis.The change from decreased to increased MCA PI along with increasing UA PI may predict a severely growth-restricted infant.