正常胎儿主肺动脉多普勒流速曲线参数测值与孕龄相关性的研究

A study on correlations between Doppler velocity waveform parameters of fetal main pulmonary artery and gestation age in normal fetus

目的探讨正常胎儿主肺动脉多普勒流速曲线参数测值与孕龄的相关性。方法将孕龄为23～40周的252例正常胎儿按照孕龄分为10组，利用超声多普勒测量胎儿主肺动脉流速曲线参数：收缩期加速时间（AT）、射血时间（ET）、加速时间／射血时间（舳T）、收缩期峰值流速（PSV）、舒张期末流速（EDV）、平均流速（MV）、搏动指数（PI）、阻力指数（RI）。建立不同孕龄各流速曲线参数的正常参考值，对各参数与孕龄绘制散点图、进行相关和回归分析，选择最优化方程。结果252例正常胎儿中，胎儿主肺动脉多普勒流速曲线测量成功249例（98．8%,249／252）。胎儿主肺动脉多普勒流速曲线参数测值随孕龄增加的变化：AT、AT／ET、PSV、EDV、MV测值随孕龄增加而呈增大趋势（F=343．23、96．012、8．649、2．158、10．169，P均〈0．05）：PI测值随孕龄增加而呈减小趋势（F=2．346，P〈0．05）；ET、RI随孕龄增加测值无明显变化（F=0．883、1．534，P〉0．05）。AT、AT／ET、PSV、EDV、MV测值与孕龄呈显著线性正相关（r=0．898、0．868、0．446、0．203、0．507，P均〈0．01）；PI测值与孕龄呈显著线性负相关（r=-0．184，P〈0．01）；ET、RI测值与孕龄无相关性（r=-0．103、0．011，P均〉0．05）。结论胎儿主肺动脉为超声多普勒测量肺动脉流速曲线的可靠测量点。正常胎儿主肺动脉流速曲线参数与孕龄有一定相关性，AT、AT／ET与胎儿孕龄相关性最好。

Objective To explore the correlations between measurements of Doppler velocity waveform parameters of fetal main pulmonary artery and gestation age （GA） in normal fetus. Methods This is a cross-sectional study, in which totally 252 normal singleton fetuses between 23 and 40 weeks of gestation were divided into 10 groups. The following velocity waveform parameters were measured in the main trunk of fetal pulmonary artery by Doppler ultrasound： acceleration time（AT）, ejection time（ET）, acceleration time/ejection time（AT/ET）, peak systolic velocity（PSV）, end diastolic velocity（EDV）, mean velocity（MV）, pulsatility index（PI） and resistance index（RI）. The normal reference values of Doppler velocity waveform parameters at various GA were established. A scatter diagram of each parameter against GA was plotted out. The optimal formula was selected out according to the correlation and regression analysis. Results Among 252 normal fetuses, satisfactory Doppler velocity waveform of fetal main pulmonary were achieved in 249 （98.8%, 249/252）. Among these parameters, AT, AT/ET, PSV, EDV and MV increased with increasing GA（F= 343.23, 96.012, 8.649, 2.158, 10.169, all P 〈 0.05）, while PI decreased slightly（F= 2.346, P 〈 0.05） and ET, KI had no significant changing（F= 0.883, 1.534, both P 〉 0.05）. Significant and positive linear correlations were found between parameters of AT, AT/ET, PSV, EDV, MV and GA（r= 0.898, 0.868, 0.446, 0.203, 0.507, all P 〈 0.01）; while PI was inversely linear correlated with GA（r=-0.184, P 〈 0.01） and ET, ILl had no correlation with GA（r=-0.103, 0.011, both P 〉 0.05）. Conclusions The fetal main pulmonary artery could be a reliable sampling point to obtain pulmonary velocity waveform by Doppler ultrasound. Doppler velocity waveform parameters have correlations with GA in normal fetus; among which AT and AT/ET were the best.