正常孕10～19周胎儿静脉导管彩色血流频谱的初步探讨

目的探讨经腹彩色多普勒超声获取10～19周胎儿静脉导管血流频谱的正确采样及检测方法并建立其阻力指数（RI）、搏动指数（PI）、心室收缩期峰值流速与心房收缩期最低流速比值（S／A）的正常参考值范围；探讨生理性零或反向房收缩（RA）波在正常10～14周胎儿静脉导管中的发生率。方法随机选取111例孕10～19周的正常单胎孕妇，在不校正测量角度的情况下进行胎儿静脉导管血流频谱检测，对血流参数RI、PI和S／A值与孕周进行相关和回归分析。结果静脉导管的血流参数值随着胎龄的增加而减低，其95％的参考值范围分别为R10．34～0．90、P10．21～1．32和S／A1．23～6．65；10～14周胎龄段的50例胎儿静脉导管血流频谱中未见零或RA波。结论应用经腹彩色多普勒超声对10～19周胎儿静脉导管进行血流动力学评价方法简单，结果准确，容易掌握；静脉导管血流参数RI、PI和S／A值随着胎龄的增加而减低，其参考值范围可进一步应用于对胎儿染色体畸形和严重心脏畸形的研究；10～14周正常胎儿静脉导管内是否存在生理性零或RA波有待于进一步研究。

Preliminary study of fetal ductus venosus flow waveforms at 10-19 weeks gestation

Objective To discuss the method of detecting fetal ductus venosus flow waveforms by trans-abdominal color Doppler ultrasound and to establish reference value ranges of resistance index(RI),pulsatility index(PI) and the ratio of the peak velocity during ventricular systole to lowest velocity during atrial systole(S/A) for fetuses at 10-19 weeks of gestation.Meanwhile,to discuss the occurrence rate of zero or reversed flow during atrial contraction(RA) in normal fetuses of 10-14 weeks of gestation.Methods(Without correcting) insonation angle,ductus venosus flow waveforms were obtained randomly from 111 singleton pregnancies at 10-19 weeks of gestation.Fetuses with chromosome malformation,severe heart malformation or growth retardation were excluded.Reference values of RI,PI and S/A were constructed by regression analysis.Results The values for RI,PI and S/A decreased with increasing gestational age.The 95% reference values of RI,PI and S/A were(0.34)-(0.90),(0.21)-(1.32) and(1.23)-(6.65) respectively.Zero or RA wave was not discovered in this study.Conclusions Assessment of ductus venosus blood flow waveforms during 10-19 weeks of gestation is feasible through trans-abdominal color Doppler.Reference value ranges of RI,PI and S/A were established in this study,and it may be utilized in further studies dealing with the role of ductus venosus blood flow in fetuses with chromosome malformation,severe heart malformation.Whether or not the physiological zero or RA wave exists in the ductus venosus of fetuses at 10-14 weeks of gestation need further investigation.