彩色多普勒超声技术测定正常中期妊娠血流的研究

采用彩色多普勒超声技术 (CDFI)测定 312例正常中期妊娠孕妇脐动脉 (UA)、胎儿大脑中动脉 (MCA)、胎儿腹主动脉 (AA)及子宫动脉 (U TA)的收缩期峰值速度 (S)、舒张末期速度 (D)、S/D比值、阻力指数 (RI)和搏动指数 (PI)。结果显示 MCA的检出较其它血管困难 ,但随孕周而检出递增。多数动脉的速度参数随孕周而升高 ,阻力参数随孕周而递减 ,与孕周相关关系有显著意义 (P<0 .0 5 ) ,而 MCA中 D随孕周变化不明显 (P>0 .0 5 ) ,其阻力值随孕周有升高倾向。逐步回归分析显示 U A的 D和 S/D、MCA的 S和 RI、AA的 S及 UTA的 RI等参数与孕周关系密切。因此认为正常中期妊娠的子宫、胎盘及胎儿血流动力学有其变化规律 ,CDFI为研究这些血管提供了有效手段

Study on the Second Trimester of the Nor mal Pregnancy by Using Color Doppler Ultrasound

Three hundred and twelve normal pregnant women in the 2nd trimester were studied by using color Doppler flow imaging (CDFI). Umbilical artery (UA), fetal middle cerebral artery (MCA), fetal abdominal aorta (AA) and uterine artery (UTA) were measured for the following blood flow parameters: the maximal systolic velocity (S), the end diastolic velocity (D), the S/D ratio, the resistance index (RI) and the pulse index (PI). It was showed that the successful rate in detecting MCA was increased with progressive gestation, but more difficult than other vessels. The flow velocities of most arteries were increased with progressive gestation, while the RI tended to decrease ( P <0 05). But the D of MCA had no significant change during the second trimester ( P <0 05) and the RI tended to increase. The step by step regression analysis showed that D and S/D of UA, S and RI of MCA, S of AA and RI of UTA had a close correlation with gestation. It was considered that hemodynamics of uterine, placental and fetal blood flow in the second trimester of the normal pregnancy had the definite changes. CDFI is a good method for studying these vessels.