Department of Obstetrics and Gynecology, Aalborg University Hospital, Aalborg, Denmark.
Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
Acta Obstet Gynecol Scand. 2018 Mar;97(3):322-329. doi: 10.1111/aogs.13289.
Current knowledge of the fetoplacental vasculature in fetal growth restriction (FGR) due to placental dysfunction focuses on the microvasculature rather than the macrovasculature. The aim of this study was to investigate the feasibility of computed tomography angiography to analyze the fetoplacental macrovasculature in normal and FGR pregnancies.
We included 29 placentas (22-42 weeks of gestation) from normal birthweight pregnancies and eight placentas (26-37 weeks of gestation) from FGR pregnancies (birthweight < -15% and abnormal umbilical Doppler flow). We performed postpartum placental computed tomography angiography followed by semi-automatic three-dimensional image segmentation.
A median of nine (range seven to eleven) vessel generations was identified. In normal birthweight placentas, gestational age was positively linearly correlated with macrovascular volume (p = 0.002), vascular surface area (p < 0.0005) and number of vessel junctions (p = 0.012), but not with vessel diameter and inter-branch length. The FGR placentas had a lower weight (p = 0.004) and smaller convex volume (p = 0.022) (smallest convex volume containing the macrovasculature); however, macrovascular volume was not significantly reduced. Hence, macrovascular density given as macrovascular outcomes per placental volume was increased in FGR placentas: macrovascular volume per convex volume (p = 0.004), vascular surface area per convex volume (p = 0.004) and number of vessel junctions per convex volume (p = 0.037).
Evaluation of the fetoplacental macrovasculature is feasible with computed tomography angiography. In normal birthweight placentas, macrovascular volume and surface area increase as pregnancy advances by vessel branching rather than increased vessel diameter and elongation. The FGR placenta was smaller; however, the macrovascular volume was within normal range because of an increased macrovascular density.
由于胎盘功能障碍导致的胎儿生长受限（FGR）中，胎儿胎盘血管目前的知识重点在于微血管，而不是大血管。本研究旨在探讨计算机断层血管造影术分析正常和 FGR 妊娠胎盘大血管的可行性。
我们纳入了 29 例（22-42 孕周）来自正常出生体重妊娠的胎盘和 8 例（26-37 孕周）来自 FGR 妊娠（出生体重 <-15%和异常脐带动脉多普勒血流）的胎盘。我们在产后进行了胎盘 CT 血管造影，然后进行半自动三维图像分割。
中位数确定了 9 个（7-11 个）血管生成。在正常出生体重的胎盘中，胎龄与大血管体积呈正线性相关（p=0.002），与血管表面积（p<0.0005）和血管分支数（p=0.012）呈正相关，但与血管直径和分支间长度无关。FGR 胎盘重量较低（p=0.004），凸面体积较小（p=0.022）（包含大血管的最小凸面体积）；然而，大血管体积没有明显减少。因此，FGR 胎盘的大血管密度增加，即大血管与胎盘体积的比值增加：凸面体积的大血管体积（p=0.004）、凸面体积的血管表面积（p=0.004）和凸面体积的血管分支数（p=0.037）。
CT 血管造影术评估胎儿胎盘大血管是可行的。在正常出生体重的胎盘中，大血管体积和表面积随着妊娠的进展而增加，这是通过血管分支而不是增加血管直径和伸长来实现的。FGR 胎盘较小，但由于大血管密度增加，大血管体积仍在正常范围内。
