Development and mechanisms of fetal hypoxia in severe fetal growth restriction
Development and mechanisms of fetal hypoxia in severe fetal growth restriction
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DOI：
10.1016/j.placenta.2006.06.007
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发表时间：
2007-07-01
期刊：
影响因子：
3.8
通讯作者：
Meschia, G.
中科院分区：
文献类型：
--
作者：
Regnault, T. R. H.;de Vrijer, B.;Meschia, G.
严重的胎儿生长受限（FGR）通常与缺氧有关。我们研究了FGR缺氧的实验模型，这是通过暴露怀孕母羊高温环境。该研究利用了几个相关因素的同时测量，例如，子宫和脐带血流量和O-2摄取。将16只母羊平均分为对照组（C）和高温组（HT）。从大约38天胎龄（dGA术语147 3天）开始，维持热疗（40 ℃持续12小时/35 ℃持续12小时;类似于35%相对湿度，RH）80天。然后将所有母羊置于对照环境（类似于21 ℃，24 h;类似于30% RH）中，并在约134 dGA下进行研究。平均HT胎盘和胎儿重量分别为C的39%和45%（p < 0.0001），脐O-2摄取/kg胎儿为C的76%（p < 0.01），脐静脉PO 2降低（20.2 vs 29.7 Torr，p < 0.001）。相反的假设，FGR缺氧是由于母体胎盘灌注不足，子宫流量没有减少有关的O-2摄取。子宫-脐静脉PO 2差异扩大（38 vs. 23 Torr，p < 0.0001）。这种差异是胎盘结构和氧化代谢的发育变化之间的平衡的表达，这在胎儿氧合方面具有相反的作用。我们推测，FGR缺氧的结果不成比例的发展不足的这些变化，使脐带O-2摄取的逐步增加。(C)2006爱思唯尔有限公司版权所有。
Severe fetal growth restriction (FGR) is often associated with hypoxia. We studied FGR hypoxia in an experimental model which is produced by exposing pregnant ewes to a hyperthermic environment. The study utilized simultaneous measurements of several relevant factors, e.g., uterine and umbilical blood flows and O-2 uptakes. Sixteen ewes were divided equally into control (C) and hyperthermic (HT) groups. Hyperthermia (40 degrees C for 12 h/35 degrees C for 12 h; similar to 35% relative humidity, RH) was maintained for 80 days commencing at approximately 38 days gestational age (dGA term 147 3 days). All ewes were then placed in a control environment (similar to 21 degrees C, 24 h; similar to 30% RH) and studied at approximately 134 dGA. Mean HT placental and fetal weights were 39% and 45% of C, respectively (p < 0.0001), umbilical O-2 uptake/kg fetus was 76% of C (p < 0.01) and umbilical venous PO2 was reduced (20.2 vs. 29.7 Torr, p < 0.001). Contrary to the hypothesis that FGR hypoxia is due to maternal placental hypoperfusion, uterine flow was not reduced in relation to O-2 uptake. The uteri ne-umbilical venous PO2 difference was enlarged (38 vs. 23 Torr, p < 0.0001). This difference is the expression of a balance between developmental changes in placental structure and oxidative metabolism, which have opposite effects in terms of fetal oxygenation. We postulate that FGR hypoxia results from disproportionate underdevelopment of those changes which allow for a progressive increase in umbilical O-2 uptake. (C) 2006 Elsevier Ltd. All rights reserved.