Functional magnetic resonance imaging (fMRI) for fetal oxygenation during maternal hypoxia: initial results.

PURPOSE: To investigate the potential of fMRI to measure changes in fetal tissue oxygenation during acute maternal hypoxia in fetal lambs.

MATERIAL AND

METHODS

Two ewes carrying singleton fetuses (gestational age 125 and 131 days) underwent MR imaging under inhalation anesthesia. BOLD imaging of the fetal brain, liver and myocardium was performed during acute maternal hypoxia (oxygen replaced by N 2 O). Maternal oxygen saturation and heart rate were monitored by a pulse-oxymeter attached to the maternal tongue.

RESULTS

Changes of fetal tissue oxygenation during maternal hypoxia were clearly visible with BOLD MRI. Signal intensity decreases were more distinct in liver and heart ( approximately 40 %) from control than in the fetal brain ( approximately 10 %).

CONCLUSIONS

fMRI is a promising diagnostic tool to determine fetal tissue oxygenation and may open new opportunities in monitoring fetal well being in high risk pregnancies complicated by uteroplacentar insufficiency. Different signal changes in liver/heart and brain may reflect a centralization of the fetal blood flow.