The importance of head growth patterns in predicting the cognitive abilities and literacy skills of small-for-gestational-age children.
This study evaluated the effects of head growth compromise beginning in utero and continuing, in some cases, through the first 9 months of life on the cognitive and literacy skills of school-age small-for-gestational-age (SGA) children. Seventy-one SGA children, aged 7 to 9 years (gestational ages, 24-41 weeks) and 16 full-term appropriate-for-gestational-age control children of comparable socioeconomic backgrounds and age at testing completed tests assessing intelligence, receptive language, working memory, problem solving, visual-motor integration, phonological awareness, reading, and spelling. SGA children were subdivided into head-growth pattern groups based on their head circumference at birth and at 9 months postterm. Analyses showed that SGA children with poor prenatal and postnatal head growth had the worst outcomes, followed by those with prenatal brain compromise, but good postnatal head growth. SGA children with preserved head growth in utero as well as good head growth after birth demonstrated the best outcomes, although spelling skills were deficient relative to full-term peers. The Verbal and Full Scale IQ ratings of the SGA children who had experienced brain compromise in utero declined significantly from 5 to 8 years of age. We conclude that mild intrauterine growth retardation (IUGR) has a minimal effect on the development of cognitive or academic abilities, providing that brain growth in utero is not affected. IUGR that slows brain growth in utero impairs the acquisition of some cognitive and academic abilities, even when followed by good catch-up head growth after birth, whereas poor brain growth in utero followed by little or no catch-up head growth results in widespread impairments. Findings highlight the limits to brain plasticity and emphasize the importance of optimal prenatal and postnatal brain growth.
Frisk
Virginia
V
Division of Neonatology and Department of Psychology The Hospital for Sick Children, Toronto, Ontario, Canada. Virginia.frisk@sickkids.ca
Amsel
Rhonda
R
Whyte
Hilary E A
HE
D001724:Birth Weight; D001827:Body Height; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002648:Child; D002657:Child Development; D003071:Cognition / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006257:Head / Q000254:growth & development*; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000254:growth & development / Q000502:physiology / Q000523:psychology*; D007361:Intelligence Tests; D007858:Learning; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D011594:Psychometrics; D011597:Psychomotor Performance / Q000502:physiology; D011932:Reading; D017678:Sex Distribution; D012959:Socioeconomic Factors