Tchirikov M, Rybakowski C, Hüneke B, Schröder H J
Universitäts-Frauenklinik Hamburg, Germany.
Am J Obstet Gynecol. 1998 May;178(5):943-9. doi: 10.1016/s0002-9378(98)70528-9.
It is known from animal experiments that blood flow through the ductus venosus changes with fetal strain. Therefore the ratio of umbilical vein to ductus venosus flow rate in human intrauterine growth retardation and multifetal pregnancies was investigated and compared with that in control subjects.
Blood flow rates in the umbilical vein and in the ductus venosus, as well as peak velocity, minimum velocity, mean velocity, and pulsatility index (maximum velocity envelope curve) in the ductus venosus, were measured in women with normal pregnancies (n = 55), intrauterine growth retardation (n = 20), and multifetal pregnancies (10 women with 20 fetuses) with color Doppler ultrasonography.
Average ductus venosus blood flow rates (mean +/- SD), normalized for estimated fetal body weight, were 60 +/- 30, 69 +/- 35, and 77 +/- 28 (ml x min(-1) x kg(-1)) in control subjects, intrauterine growth retardation, and multifetal pregnancies, respectively. Umbilical vein blood flow rates amounted to 140 +/- 59, 111 +/- 54, and 141 +/- 47 (ml x min(-1) x kg(-1)). Both absolute flow rates increased with gestational age, whereas normalized flow rates decreased. The percentage of umbilical blood flow passing through the ductus venosus in the control group was 43% + 9%. It was significantly increased in both intrauterine growth retardation (62% +/- 8%) and in multifetal pregnancies (55% +/- 12%). Peak velocity, minimum velocity, mean velocity, and pulsatility index in the ductus venosus were not significantly different between groups.
The increased ratio of ductus venosus blood flow to umbilical vein blood flow may indicate fetal strain.
动物实验表明，经静脉导管的血流量会随胎儿应变而变化。因此，本研究对人类宫内生长受限和多胎妊娠中脐静脉与静脉导管血流速率的比值进行了调查，并与对照组进行了比较。
采用彩色多普勒超声测量了正常妊娠女性（n = 55）、宫内生长受限女性（n = 20）和多胎妊娠女性（10名女性，20个胎儿）的脐静脉和静脉导管内的血流速率，以及静脉导管内的峰值速度、最小速度、平均速度和搏动指数（最大速度包络曲线）。
根据估计的胎儿体重进行标准化后，对照组、宫内生长受限组和多胎妊娠组的平均静脉导管血流速率（均值±标准差）分别为60±30、69±35和77±28（ml·min⁻¹·kg⁻¹）。脐静脉血流速率分别为140±59、111±54和141±47（ml·min⁻¹·kg⁻¹）。两种绝对血流速率均随胎龄增加而升高，而标准化血流速率则降低。对照组中经静脉导管的脐血流量百分比为43% + 9%。在宫内生长受限组（62%±8%）和多胎妊娠组（55%±12%）中，该百分比均显著升高。各组之间静脉导管的峰值速度、最小速度、平均速度和搏动指数无显著差异。
静脉导管血流与脐静脉血流比值的增加可能表明胎儿存在应变。
