title: Fetoplacental vascular alterations associated with fetal growth restriction.
abstract: BACKGROUND
  Placental functional impairment in pregnancies with fetal growth restriction (FGR) can arise from fetoplacental vascular abnormalities. We aimed to compare the micro and macrovasculature of placentas from normal pregnancies with those showing late onset FGR.
  
  
  METHODS
  Placental arterial casts (n = 12 normal, 6 FGR) were prepared. Chorionic arterial number and inter-branch length were examined. Microvascular features were quantified in CD34-stained tissue sections obtained by systematic (n = 12 normal, 12 FGR) and targeted (n = 6 normal, 6 FGR) sampling from the placental periphery and centre.
  
  
  RESULTS
  Adjusted for the weight of the placenta or the surface area of the chorionic plate, the number of chorionic arteries was similar in normal and FGR arterial casts. Inter-branch length per unit placental weight was greater in the first generation of arterial branches in FGR (p < 0.05). Villi in FGR placentas were more poorly vascularised, particularly at the periphery and in grossly visible hypovascular regions. Intermediate and terminal FGR villi in these areas exhibited reduced vessel lumens, loss of CD34, and infilling with CD34-negative cells of what appeared to be previously existing vascular spaces.
  
  
  CONCLUSIONS
  Differences in chorionic arterial branching patterns between normal and FGR placentas arise from differences in placental size. FGR placentas show microvascular regression and extreme hypovascularity in peripheral areas. These features may well limit the ability of the placenta to meet fetal nutrient requirements late in gestation. Targeted sampling is more effective than systematic random sampling in revealing vascular defects.
authors.affiliation: Maternal and Fetal Health Research Centre, Institute of Human Development, Manchester Academic Health Science Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, University of Manchester, Manchester M13 9WL, UK. Electronic address: toluwalope.junaid@postgrad.manchester.ac.uk.
authors.forename: T O
authors.initials: TO
authors.lastname: Junaid
authors.affiliation: Maternal and Fetal Health Research Centre, Institute of Human Development, Manchester Academic Health Science Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, University of Manchester, Manchester M13 9WL, UK.
authors.forename: P
authors.initials: P
authors.lastname: Brownbill
authors.affiliation: Department of Radiology, Manchester Royal Infirmary, Central Manchester University Hospitals NHS Foundation Trust, Manchester M13 9WL, UK.
authors.forename: N
authors.initials: N
authors.lastname: Chalmers
authors.affiliation: Maternal and Fetal Health Research Centre, Institute of Human Development, Manchester Academic Health Science Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, University of Manchester, Manchester M13 9WL, UK.
authors.forename: E D
authors.initials: ED
authors.lastname: Johnstone
authors.affiliation: Maternal and Fetal Health Research Centre, Institute of Human Development, Manchester Academic Health Science Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, University of Manchester, Manchester M13 9WL, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Aplin
mesh_terms: D000328:Adult; D005260:Female; D005317:Fetal Growth Retardation / Q000473:pathology* / Q000503:physiopathology; D005333:Fetus / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D010920:Placenta / Q000098:blood supply* / Q000473:pathology / Q000503:physiopathology; D011247:Pregnancy; D055815:Young Adult
keywords: Fetal growth restriction; Fetoplacental vasculature; Hypovascularity; Vascular casts