Scherjon S, Briët J, Oosting H, Kok J
Graduate School Neurosciences Amsterdam, Academic Medical Center, University of Amsterdam, The Netherlands.
Pediatrics. 2000 Feb;105(2):385-91. doi: 10.1542/peds.105.2.385.
After intrauterine growth restriction we found at the age of 6 months an acceleration of neurophysiologic maturation. However, at later ages impaired cognitive outcome has been reported. Therefore, we investigated in children with and without fetal hemodynamic adaptation to intrauterine growth restriction whether the accelerated neurophysiologic maturation in infancy might be associated with impaired cognitive outcome at preschool age.
At 5 years of age cognitive function was assessed using the Revision of the Amsterdam Children's Intelligence Test in 73 preterm infants (26-33 weeks) who were prospectively followed from the antenatal period up to the age of 5 years. Maternal educational level was used as a background variable to estimate the confounding effects of socioeconomic status on cognitive function. Fetal Doppler studies were performed and the umbilical artery pulsatility index (PI) divided by the middle cerebral artery PI ratio (U/C ratio) was calculated. A U/C ratio >0.725 was considered as an indication of fetal cerebral hemodynamic adaptation to a compromised placental perfusion, ie, fetal brain-sparing. Visual-evoked potentials (VEPs) were recorded at 6 months and 1 year of age. In addition, data on neurologic status at 3 years were available.
Mean IQ score was significantly lower for children born with a raised U/C ratio (87 +/- 16) compared with children with a normal U/C ratio (96 +/- 17). VEP latencies decreased significantly in infants with a normal U/C ratio, whereas no decrease was found in infants with a raised U/C ratio. Variables contributing significantly to the variance of cognitive function were: U/C group, VEP latency maturation, level of maternal education, and neurodevelopmental outcome at 3 years. The linear regression model explained 33% of the variance in cognitive function.
Both being born with a raised U/C ratio and an acceleration of VEP latencies are negatively associated with cognitive outcome at 5 years of age. Fetal brain-sparing, although a seemingly beneficial adaptive mechanism for intact neurologic survival, is, however, later associated with a poorer cognitive outcome.
我们发现在宫内生长受限后，6个月大时神经生理成熟加速。然而，据报道在更大年龄时认知结果受损。因此，我们调查了有或没有胎儿血流动力学适应宫内生长受限的儿童，婴儿期加速的神经生理成熟是否可能与学龄前认知结果受损有关。
在5岁时，使用阿姆斯特丹儿童智力测试修订版对73名早产儿（26 - 33周）的认知功能进行评估，这些早产儿从孕期开始就进行前瞻性随访直至5岁。母亲教育水平作为背景变量，用于评估社会经济地位对认知功能的混杂影响。进行胎儿多普勒研究并计算脐动脉搏动指数（PI）除以大脑中动脉PI比值（U/C比值）。U/C比值>0.725被视为胎儿脑血流动力学适应胎盘灌注受损的指标，即胎儿脑保护。在6个月和1岁时记录视觉诱发电位（VEP）。此外，还可获得3岁时的神经学状态数据。
与U/C比值正常的儿童（96±17）相比，U/C比值升高的儿童出生时平均智商得分显著更低（87±16）。U/C比值正常的婴儿VEP潜伏期显著缩短，而U/C比值升高的婴儿未发现潜伏期缩短。对认知功能方差有显著贡献的变量包括：U/C组、VEP潜伏期成熟度、母亲教育水平和3岁时的神经发育结果。线性回归模型解释了认知功能方差的33%。
出生时U/C比值升高和VEP潜伏期加速均与5岁时的认知结果呈负相关。胎儿脑保护虽然看似是一种对神经功能完整存活有益的适应性机制，但随后却与较差的认知结果相关。
