Lindsay S. Cahill1, Yu-Qing Zhou1, Mike Seed, Christopher K. Macgowan, 2, John G. Sled1, 2
1Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada; 2Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
Fetal growth restriction is often associated with brain sparing whereby a greater proportion of oxygenated fetal blood is directed to the brain at the expense of other organs. Understanding the physiology of this response may lead to better diagnostic procedures for predicting fetal risk. Here, BOLD MRI contrast is used to characterize the redistribution of fetal blood flow that occurs in mice under hypoxic conditions. As the maternal inspired gas mixture is varied, large BOLD signal changes were observed in the fetal liver but not in the brain. Using Doppler ultrasound, cerebral blood flow was observed to rise under hypoxia.