Effect of Intrauterine Inflammation on Fetal Cerebral Hemodynamics and White-matter Injury in Chronically Instrumented Fetal Sheep

Objective: The purpose of this study was to analyze the effects of intrauterine inflammation on cerebral hemodynamics and white-matter injury in premature fetal sheep.

Study Design: Fetuses were given an intravenous infusion of granulocyte colony-stimulating factor and an intraamniotic infusion of endotoxin; the fetuses were then assigned randomly to an acute hemorrhage group, an exchange transfusion group, or a control group. During each insult, the cerebral hemodynamics were assessed with near-infrared spectroscopy. Finally, the fetuses were processed for neuropathologic analysis and compared statistically.

Results: Necrotizing funisitis and chorioamnionitis were induced in all the fetuses. A significant decrease in the blood oxygen content and an increase in the brain total hemoglobin level were observed after the endotoxin infusion. Soon after hemodynamic insult, the fetuses in both the acute hemorrhage and the exchange transfusion groups showed an abrupt decrease in the total brain hemoglobin level; 4 of the 5 fetuses in each treatment group, but none of the fetuses in the control group, exhibited periventricular leukomalacia.

Conclusion: Hemorrhagic hypotension or anemic hypoxemia might induce a sudden cessation of fetal brain-sparing effects through progressive inflammatory hypoxemia, which results in focal white-matter injuries.