Disorders of the fetal circulation and the fetal brain.

Even in the presence of normal placental function, cerebral oxygen-substrate supply may be disrupted by disturbances in the fetal circulation caused by anomalous cardiac development. The impact of these cardiac lesions is likely dictated primarily by the volume and oxygen-substrate composition of transverse aortic arch perfusion. Advances in fetal echocardiography, fetal Doppler ultrasound, and advanced fetal magnetic resonance imaging techniques capable of quantitative structural and functional measurements are providing major insights into the in vivo effects of these cardiac lesions on brain growth and development. The progress to date with the application of these techniques is reviewed in this article.