Sutton M S, Theard M A, Bhatia S J, Plappert T, Saltzman D H, Doubilet P
Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.
Pediatr Res. 1990 Oct;28(4):383-7. doi: 10.1203/00006450-199010000-00016.
We assessed fetoplacental blood volume flow and placental resistance prospectively with Doppler sonography in 74 normal human fetuses of 19 to 42 wk gestation to determine the changes in placental perfusion with gestational age. Placental blood volume flow was assessed from the umbilical vein as the product of the mean flow velocity integral and the cross-sectional area of the umbilical vein. Placental resistance was assessed as the ratio of maximum systolic and minimum diastolic blood flow velocities from an umbilical artery. Umbilical vein blood volume flow increased exponentially (r = 0.86) with gestational age from 19 wk to term, and did not decrease in postdate fetuses. Umbilical vein blood volume flow increased linearly with fetal weight (r = 0.77), although volume flow per unit body weight changed little with gestational age. Umbilical artery velocity ratio decreased progressively, indicating diminishing placental resistance with gestational age, but did not correlate closely with umbilical vein blood volume flow. We submit that fetoplacental blood volume flow can be readily calculated directly from the umbilical vein with Doppler ultrasound and may provide a better index of placental perfusion than the umbilical artery velocity ratio.
我们采用多普勒超声前瞻性评估了74例孕19至42周正常人类胎儿的胎儿-胎盘血容量流量及胎盘阻力，以确定胎盘灌注随孕周的变化。胎盘血容量流量通过脐静脉进行评估，计算方法为平均流速积分与脐静脉横截面积的乘积。胎盘阻力通过脐动脉的最大收缩期与最小舒张期血流速度之比进行评估。从孕19周直至足月，脐静脉血容量流量随孕周呈指数增长（r = 0.86），过期胎儿的该指标并未下降。脐静脉血容量流量随胎儿体重呈线性增加（r = 0.77），尽管单位体重的血容量流量随孕周变化不大。脐动脉速度比逐渐降低，表明胎盘阻力随孕周减小，但与脐静脉血容量流量并无密切关联。我们认为，利用多普勒超声可直接从脐静脉轻松计算胎儿-胎盘血容量流量，相较于脐动脉速度比，它可能是更好的胎盘灌注指标。
