Foetal cerebral redistribution or 'brain-sparing' is a diagnosis in foetal medicine. It is characterised by preferential flow of blood towards the brain at the expense of the other vital organs, and it occurs as a haemodynamic adaptation in foetuses which have placental insufficiency. [1] The underlying mechanism is thought to be vasodilation of the cerebral arteries. [2] Cerebral redistribution is defined by the presence of a low middle cerebral artery pulsatility index (MCA-PI). Ultrasound of the middle cerebral artery to examine the Doppler waveform is used to establish this. [3] Although cerebral redistribution represents an effort to preserve brain development in the face of hypoxic stress, it is nonetheless associated with adverse neurodevelopmental outcome. [1] The presence of cerebral redistribution will be one factor taken into consideration when deciding whether to artificially deliver a baby with placental insufficiency via induction of labour or caesarian section.
