Fetal brain sparing is associated with accelerated shortening of visual evoked potential latencies during early infancy

OBJECTIVE: Our purpose was to assess the effects that fetal growth restriction exerts on the myelination of the developing brain. STUDY DESIGN: Fetal haemodynamic centralization, an adaptive strategy to growth restriction caused by placental insufficiency, was determined by Doppler ultrasonography. Infants with a raised ratio between umbilical artery pulsatility index and cerebral artery pulsatility index are severely growth restricted. Visual evoked potentials give information on the degree of brain myelination. Shortening of visual evoked potential latencies is a normal feature of myelination. In a consecutive series of 105 neonates, visual evoked potentials were recorded at the corrected ages of 6 months and 1 year. Correction for possible confounders, such as cranial ultrasonographic findings, gestational age, and head circumference, was performed. RESULTS: At 6 months, infants with a raised umbilical artery/cerebral artery pulsatility index ratio have shorter visual evoked potential latencies. Opposite of neonates with a normal umbilical artery/cerebral artery ratio, they show no postnatal maturational shortening of visual evoked potential latencies. CONCLUSION: Accelerated neurophysiologic maturation, found in infants with a high umbilical artery/cerebral artery ratio, might be the result of a beneficial adaptive process to severe fetal growth restriction. (Am J Obstet Gynecol 1996;175:1569-75.)