[Prediction of IQ among children with birth weight under 1, 501 gms].
BACKGROUND
As a group, preterm infants are at considerable risk of cognitive difficulties. However, predicting cognitive sequelae has proved to be difficult. The current study reports on prediction of IQ at age eight years on the basis of the children's perinatal and developmental status, as well as parental socioeconomic status.


METHODS
The sample consisted of 104 infants with birth weight < or = 1,501 g (53 girls), recruited consecutively in the neonatal intensive care unit and followed up to age eight years. Perinatal status, early cognitive development, and parental socioeconomic status served as predictors. Cognitive ability assessed on two commonly used intelligence tests served as outcome. The participants did not represent a total population, and no control group was used.


RESULTS
Regression analyses revealed that birth weight, the Bayley cognitive index at 39 and 56 weeks, and parental socioeconomic status all made significant and independent contributions to outcome. Though the Bayley index made no significant contribution at age 29 weeks, it was the only variable at age two that was related to IQ at age eight.


CONCLUSIONS
Perinatal data are generally of limited value for the prediction of later IQ among preterm infants. However, when combined with information about parental socioeconomic status and the infants' developmental status up to age 56 weeks, birth weight made a unique and significant contribution as a predictor of later IQ. At age two years the cognitive status of prematurely born children was sufficiently consolidated to yield a valid prediction of outcome.
Smith
L
L
Psykologisk institutt Universitetet i Oslo Postboks 1094 Blindern 0317 Oslo. lars.smith@psykologi.uio.no
Ulvund
S E
SE
Lindemann
R
R
D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000523:psychology; D019102:Infant, Very Low Birth Weight / Q000523:psychology*; D007360:Intelligence; D007361:Intelligence Tests; D008297:Male; D009664:Norway; D011247:Pregnancy; D011379:Prognosis; D012307:Risk Factors; D012959:Socioeconomic Factors