title: Real-Time Monitoring of Placental Oxygenation during Maternal Hypoxia and Hyperoxygenation Using Photoacoustic Imaging.
abstract: OBJECTIVE
  This preclinical study aimed to evaluate placental oxygenation in pregnant rats by real-time photoacoustic (PA) imaging on different days of gestation and to specify variations in placental oxygen saturation under conditions of maternal hypoxia and hyperoxygenation.
  
  
  METHODS
  Placentas of fifteen Sprague-Dawley rats were examined on days 14, 17, and 20 of pregnancy with a PA imaging system coupled to high-resolution ultrasound imaging. Pregnant rats were successively exposed to hyperoxygenated and hypoxic conditions by changing the oxygen concentration in inhaled gas. Tissue oxygen saturation was quantitatively analyzed by real-time PA imaging in the skin and 3 regions of the placenta. All procedures were performed in accordance with applicable ethical guidelines and approved by the animal care committee.
  
  
  RESULTS
  Maternal hypoxia was associated with significantly greater decrease in blood oxygen saturation (ΔO2 Saturation) in the skin (70.74% ±7.65) than in the mesometrial triangle (32.66% ±5.75) or other placental areas (labyrinth: 18.58% ± 6.61; basal zone: 13.13% ±5.72) on different days of pregnancy (P<0.001). ΔO2 Saturation did not differ significantly between the labyrinth, the basal zone, and the decidua. After the period of hypoxia, maternal hyperoxygenation led to a significant rise in oxygen saturation, which returned to its initial values in the different placental regions (P<0.001).
  
  
  CONCLUSIONS
  PA imaging enables the variation of blood oxygen saturation to be monitored in the placenta during maternal hypoxia or hyperoxygenation. This first preclinical study suggests that the placenta plays an important role in protecting the fetus against maternal hypoxia.
authors.affiliation: Inserm U930, François Rabelais University, Tours, France.|University Hospital Center of Tours, Department of Obstetrics, Gynecology and Fetal Medicine, Tours, France.
authors.forename: Chloé J
authors.initials: CJ
authors.lastname: Arthuis
authors.affiliation: Inserm U930, François Rabelais University, Tours, France.
authors.forename: Anthony
authors.initials: A
authors.lastname: Novell
authors.affiliation: PHENOMIN-TAAM-UPS44, Center for Small Animal Imaging (CIPA), CNRS Orléans, France.
authors.forename: Florian
authors.initials: F
authors.lastname: Raes
authors.affiliation: Inserm U930, François Rabelais University, Tours, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Escoffre
authors.affiliation: PHENOMIN-TAAM-UPS44, Center for Small Animal Imaging (CIPA), CNRS Orléans, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Lerondel
authors.affiliation: PHENOMIN-TAAM-UPS44, Center for Small Animal Imaging (CIPA), CNRS Orléans, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Le Pape
authors.affiliation: Inserm U930, François Rabelais University, Tours, France.
authors.forename: Ayache
authors.initials: A
authors.lastname: Bouakaz
authors.affiliation: Inserm U930, François Rabelais University, Tours, France.|University Hospital Center of Tours, Department of Obstetrics, Gynecology and Fetal Medicine, Tours, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Perrotin
mesh_terms: D000818:Animals; D003952:Diagnostic Imaging; D005260:Female; D018496:Hyperoxia / Q000097:blood / Q000000981:diagnostic imaging; D000860:Hypoxia / Q000097:blood / Q000000981:diagnostic imaging; D010100:Oxygen / Q000097:blood*; D061088:Photoacoustic Techniques; D010920:Placenta; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000000981:diagnostic imaging; D051381:Rats
chemical_list: D010100:Oxygen