Cognitive outcome varies in adolescents born preterm, depending on gestational age, intrauterine growth and neonatal complications.
OBJECTIVE
The aim of this study was to investigate long-term cognitive outcome in a cohort of 18-year-olds born preterm and previously assessed at the age of 5.5.


METHODS
We tested 134 adolescents born preterm with a very low birthweight of <1500 g and 94 term-born controls with a comprehensive cognitive battery at 18 years of age. The cohort was subdivided into 73 extremely preterm, 42 very preterm and 19 moderately preterm infants with gestational ages of 23-27, 28-31 and 32-36 weeks, respectively. The moderately preterm group was dominated by adolescents born small for gestational age.


RESULTS
Very preterm adolescents performed on a par with term-born controls. In contrast, extremely preterm adolescents displayed inferior results on all cognitive tests, more so if they had suffered neonatal complications. Moderately preterm adolescents scored lower than very preterm and full-term born adolescents, particularly on complex cognitive tasks.


CONCLUSIONS
Adolescents born at 28 weeks of gestation or later, with appropriate birthweight and no perinatal complications, functioned like term-born peers at 18 years of age. Extremely preterm birth per se posed a risk for long-term cognitive deficits, particularly executive deficits. Adolescents born moderately preterm but small for gestational age were at risk of general cognitive deficits.
Department of Psychology, Stockholm University, Stockholm, Sweden; Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
Aiko
A
Lundequist
Birgitta
B
Böhm
Hugo
H
Lagercrantz
Hans
H
Forssberg
Ann-Charlotte
AC
Smedler
D000293:Adolescent; D041923:Adolescent Development; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases; D007236:Infant, Small for Gestational Age; D019102:Infant, Very Low Birth Weight; D008297:Male; D011446:Prospective Studies; D011581:Psychological Tests; D012307:Risk Factors
Adolescents; Long-term cognitive outcome; Medical complications; Preterm birth; Small for gestational age