Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
BMJ Paediatr Open. 2022 Apr;6(1). doi: 10.1136/bmjpo-2021-001361.
Recent longitudinal studies suggest stable cognitive development in preterm children, although with great individual variation. This prospective neurocognitive follow-up study of extremely low birthweight (ELBW, <1000 g) children aimed to characterise groups with different developmental trajectories from preschool to preteen age.
ELBW children (n=115) born in Finland in 1996-1997 participated in cognitive assessments at a median age of 5.0 years and 11.3 years. A standardised test of intelligence (Wechsler Preschool and Primary Scale of Intelligence-Revised or Wechsler Intelligence Scale for Children-third edition) was administered at both ages.
Three ELBW groups with different developmental trajectories over time were identified with latent class growth analysis. Children with average (Full-Scale IQ (FSIQ): 85-115) and below average (FSIQ: <85) intelligence at 5 years of age had significant decreases in intelligence scores by 11 years of age (-11.7 points and -14.9 points, respectively, both p<0.001), while those with above average intelligence (FSIQ: >115) showed stable development (-3.2 points, p=0.250). Multiple linear regression showed that neonatal complications (intraventricular haemorrhage grade 3-4 and blood culture positive sepsis) and maternal education significantly predicted lower intelligence at the second assessment (F(3,106)=7.27, p<0.001, adjusted R=0.147).
ELBW children represent a heterogeneous patient population in which groups with different cognitive trajectories can be detected. Deterioration may occur particularly in children with initial average or below average cognitive performance at 5 years of age, with neonatal complications and lower maternal education presenting as risk factors. Catch-up in cognitive functions seems more uncommon in the ELBW population, which should be noted in clinical work.
最近的纵向研究表明，早产儿的认知发展较为稳定，尽管存在较大的个体差异。本研究对极低出生体重儿（ELBW，<1000g）进行了前瞻性神经认知随访，旨在描述从学前到青春期不同发展轨迹的组别特征。
1996-1997 年在芬兰出生的 ELBW 儿童参与了认知评估，中位数年龄为 5.0 岁和 11.3 岁。在这两个年龄阶段，均采用了标准化的智力测试（韦氏学前和小学智力量表修订版或韦氏儿童智力量表第三版）。
采用潜在类别增长分析确定了 3 个具有不同时间发展轨迹的 ELBW 组。5 岁时智力处于平均水平（全量表智商（FSIQ）：85-115）和低于平均水平（FSIQ：<85）的儿童，11 岁时的智力评分显著下降（分别下降 11.7 分和 14.9 分，均 p<0.001），而智力高于平均水平（FSIQ：>115）的儿童则表现出稳定的发展（下降 3.2 分，p=0.250）。多元线性回归显示，新生儿并发症（脑室出血 3-4 级和血培养阳性败血症）和母亲教育水平显著预测了第二次评估时的较低智力（F(3,106)=7.27，p<0.001，调整后的 R=0.147）。
ELBW 儿童是一个异质性的患者群体，可以检测到不同认知轨迹的组别。在 5 岁时认知表现处于平均或低于平均水平的儿童中，可能会出现恶化的情况，新生儿并发症和较低的母亲教育水平是风险因素。在 ELBW 人群中，认知功能的追赶似乎不太常见，这在临床工作中需要注意。
