Umbilicocerebral ratio: potential implications of inversing the cerebroplacental ratio

Increased cerebral blood flow in response to hypoxia is a well-defined regulatory mechanism in humans1. Fetuses show a similar response to hypoxia by reducing the impedance to flow in the cerebral arteries2. Investigation of such an effect in growth-restricted fetuses is commonly performed by Doppler assessment of the fetal middle cerebral artery (MCA). However, the standalone accuracy of MCA Doppler for the prediction of adverse outcome appears...