血液动力学指标预测胎儿缺氧及酸中毒的价值

Colour Doppler Ultrasonographic Indices in Predicting Fetal Hypoxia and Acidosis

目的：评价血液动力学指标预测胎儿缺氧及酸中毒的价值。方法：用彩色多普勒超声检测了４６例正常晚期妊娠（正常组）和３２例高危妊娠（高危组）妇女子宫动脉（ＵｔＡ）和胎儿脐动脉（ＵｍＡ）、大脑中动脉（ＭＣＡ）、肾动脉（ＲＡ）的血流速度波型，并且测定高危组脐动脉血气。结果：高危组ＵｔＡ、ＵｍＡ、ＲＡ的阻力指数（ＲＩ）、搏动指数（ＰＩ）及收缩期最大血流速度（Ｓ）与舒张末期血流速度（Ｄ）的比值（Ｓ／Ｄ值）均高于正常组，而ＭＣＡ的ＰＩ及Ｓ／Ｄ值均明显低于正常组（Ｐ＜０．０５）。与ＵｍＡＰＯ２＞２．５ｋＰａ的高危妊娠病例比较，ＵｍＡＰＯ２≤２．５ｋＰａ者ＵｔＡ的Ｓ／Ｄ值、ＵｍＡ的ＰＩ、Ｓ／Ｄ值以及ＲＡ的ＲＩ、ＰＩ、Ｓ／Ｄ值均明显增高，ＭＣＡ的ＰＩ明显降低（Ｐ＜０．０５）。ＵｍＡ及ＲＡ的ＰＩ与ＵｍＡＰＯ２和ｐＨ值呈负相关，与ＰＣＯ２呈正相关；ＭＣＡ的ＰＩ与ＵｍＡ的ｐＨ、ＰＯ２呈正相关，与ＰＣＯ２呈负相关。结论：高危妊娠胎儿缺氧时ＭＣＡ血流阻力降低，而周围血管，特别是肾血管血流阻力明显升高；胎儿血液动力学变化与缺氧及酸碱平衡失调呈良好相关性，可预测胎儿缺氧及酸中毒的程度。

Objective: To evaluate the effect of uterine placental fetal blood flow velocity waveforms (FVWs) on prdicting fetal hypoxia and acidosis in high risk pregnancy. Methods: 46 women of normal term pregnancy (normal group) and 32 women of high risk term pregnancy (high risk group) were examined with colour Doppler ultrasound for their FVWs including maternal uterine artery (UtA), fetal umbilical artery (UmA), middle cerebral artery (MCA), and renal artery (RA). Umbilical artery blood gases were analysed at delivery in high risk group. Results: The resistance index (RI), pulsatile index (PI) and ratio of peak systolic to least diastolic flow velocity (S/D) of UtA, UmA and RA were higher and the PI, S/D of MCA was lower significantly in the high risk group than that of normal the group ( P <0.05). In the high risk pregnancy, when UmA PO 2 was less than 2.5 kPa, the S/D of UtA, PI, S/D of UmA and RI, PI, S/D of RA were increased, and the PI of MCA was decreased ( P <0.05). There were a positive correlation between PI of UmA, RA and PO 2, pH of UmA, and a negative correlation between the former and PCO 2 of UmA. But there were a negative correlation between PI of MCA and PO 2, pH of UmA, and a positive correlation between the former and UmA PCO 2. Conclusion: In the high risk pregnancy, fetal cerebral blood flow increased, whereas blood flow of fetal peripheral vessels (especially renal vessel) decreases. There is a good correlation between fetal hypoxia and fetal blood FVWs. The indices of the fetal blood FVMs can identify fetal hypoxia and acidosis.