Cerebral blood flow studies in the diagnosis and management of intrauterine growth restriction

Purpose of review To provide evidence that fetal brain vasodilatation can be related with postnatal cerebral structural and functional complications. Recent findings Most early-onset intrauterine growth restricted (IUGR) fetuses show signs of brain vasodilatation. As most of them are born prematurely, a high prevalence of short-term and long-term neurological complications is expected. However, the clinical significance of brain vasodilatation might be different. In the early stage of fetal deterioration, the risk of structural brain damage is low, but at advanced stages there is an increased risk of periventricular leukomalacia and intraventricular hemorrhage. The presence of brain vasodilatation in fetuses with an estimated fetal weight below the 10th centile but normal umbilical artery Doppler can be used to identify late-onset IUGR fetuses with latent placental insufficiency. These fetuses have an increased risk of abnormal neurological performance at birth and at 2 years of age. Summary Changes in cerebral brain blood perfusion in IUGR fetuses can be detected by Doppler ultrasound techniques. Despite its association with structural and functional neurological damage after birth, fetal brain vasodilatation is usually not considered in the decision to deliver, with the only exception of the 'return' to normal middle cerebral artery pulsatility index, which is highly associated with an increased risk for perinatal mortality.