Quantitative 3D Micro-CT Imaging of the Human Feto-placental Vasculature in Intrauterine Growth Restriction

Abstract 

Objective

Placental vascular development matches fetal growth and development. Quantification of the feto-placental vasculature in placentas from pregnancies is complicated by intrauterine growth restriction (IUGR) revealed confounding results. Therefore, the feto-placental vascular volume in IUGR placentas was assessed by 3D micro-computed tomography (micro-CT).

Methods and results

Placental probes from IUGR (n=24) and healthy control placentas (n=40) were perfused in situ with Microfil or BaSO₄ and randomly chosen samples were scanned by micro-CT. Using 3D images, we quantitated the feto-placental vascular volume fraction (VVF). A subanalysis was performed at three different levels, reaching from the chorionic plate artery (level A), to intermediate arteries (level B) and capillary system (level C). Results were complemented by histology. The significance of differences in vascular volume measurements was tested with analysis of variance [ANOVA].

Results

Microfil perfused placentas showed a total vascular volume fraction of 20.5±0.9% in healthy controls. In contrast, the VVF decreased to 7.9±0.9% (p<0.001) in IUGR placentas. Significant differences were found between Microfil and BaSO₄ perfused placentas in the vascular volume fraction using micro-CT and histology. Micro-CT demonstrated localized concentric luminal encroachments in the intermediate arteries in placentas complicated by IUGR.

Conclusion

Micro-CT imaging is feasible for quantitative analysis of the feto-placental vascular tree in healthy controls and pregnancies complicated by IUGR.

Keywords: Micro-CT, Feto-placental vasculature, Intrauterine growth restriction