中晚孕期正常胎儿大脑前动脉血流参数与孕周的相关性

目的：探讨中晚孕期正常妊娠胎儿大脑前动脉(anterior cerebral artery，ACA)2个解剖节段(S1和S2)血流动力 学参数与孕周的相关性。方法：经常规超声检查后用能量多普勒及脉冲多普勒分别检测288例20~40周正常妊娠胎儿 ACA(ACAS1和ACAS2)的收缩期峰值流速(peak systolic velocity，PSV)、舒张末期血流速度(end diastolic velocity，EDV)、 时间-平均最大流速(time-average maximum velocity，TAMAXV)、收缩期峰值血流速度/舒张末期血流速度(systolic blood flow velocity/end-diastolic blood flow velocity，S/D)、阻力指数(resistance index，RI)及搏动指数(pulsation index，PI)；将 各参数与孕周的关系分别绘制散点图，拟合多种回归模型，选出最佳拟合曲线并得出相关公式；并对比分析ACAS1 与ACAS2各血流动力学指标间的差异性。结果：ACAS1和ACAS2的PSV，EDV，TAMAXV与妊娠周数均呈正相关 (P<0.001)，均以Cubic曲线拟合优度最佳；ACAS1和ACAS2的S/D，PI，RI值与孕周均无相关关系(P>0.05)；ACAS1的 PSV，TAMAXV，S/D，PI及RI值均明显高于ACAS2， ACAS1的EDV值低于ACAS2(P<0.05)。结论：中晚孕期正常妊娠 胎儿ACA两个解剖节段(ACAS1和ACAS2)速度参数(PSV，EDV，TAMAXV)随孕周增加而增高，阻力参数(S/D，PI， RI)与孕周无明显相关性。ACAS1与ACAS2供血区域存在血流差异性分布。

Blood flow parameters in fetal anterior cerebral artery during the second and third trimester of gestation

Objective: To investigate hemodynamic parameters in 2 anatomical segments (S1 and S2) of anterior cerebral artery (ACA) in normal pregnancy during the second and third trimester of gestation. Methods: Th e peak systolic velocity (PSV), end diastolic velocity (EDV), time-average maximum velocity (TAMAXV), peak systolic velocity/end diastolic velocity (S/D), resistance index (RI), and pulsation index (PI) in S1 and S2 of fetal anterior cerebral artery (ACA) in 288 normal pregnant women were detected by power Doppler and pulsed Doppler. Multiple regression models were fitted to estimate the relation between Doppler variables and gestational age. The differences of hemodynamic parameters between ACAS1 and ACAS2 were compared. Results: The PSV, EDV, and TAMAXV of ACAS1 and ACAS2 were positively correlated with the weeks of pregnancy (P<0.001), all fitted with the cubic curve. The S/D, PI, and RI values of ACAS1 and ACAS2 were not correlated with gestational ages (P>0.05). The PSV, TAMAXV, S/D, PI, and RI of ACAS1 were significantly higher than those of ACAS2, while EDV in ACAS1 was lower than that in ACAS2 (P<0.05). Conclusion: The velocity parameters (PSV, EDV, TAMAXV) of the 2 anatomical segments (ACAS1 and ACAS2) are increased with the increase of gestational age in normal pregnant fetus during the second and third trimester of gestation, and the resistance parameters (S/D, PI, RI) are not significantly correlated with gestational age. Distribution of blood flow is different in the blood supply territory between ACAS1 and ACAS2.