Change in cognitive function over time in very low-birth-weight infants.
BACKGROUND
Preterm very low-birth-weight (VLBW) infants have a high prevalence of neurodevelopmental disability when evaluated during the first several years of life. However, recent experimental data suggest that the developing brain may recover from or compensate for injury.


OBJECTIVE
To determine if there is cognitive improvement throughout early and middle childhood following VLBW birth.


METHODS
Follow-up data of 296 infants born weighing 600 to 1250 g who participated in a prospective, randomized, placebo-controlled intraventricular hemorrhage (IVH) prevention study performed at 3 northeastern US hospitals between September 1989 and August 1992 and who were serially evaluated at 36, 54, 72, and 96 months of corrected age (CA).


METHODS
The age-normed Peabody Picture Vocabulary Test-Revised (PPVT-R) score and measures of intelligence.


RESULTS
Overall, the median PPVT-R score increased from 88 at 36 months of CA to 99 at 96 months of CA; when data from 36 and 96 months of CA were compared, 45% of children gained 10 points or more and 12.5% showed a 5- to 9-point increase in test scores. Similar findings were noted for full-scale and verbal IQ scores. Multivariate analyses demonstrated that increasing age, residence in a 2-parent household, and higher levels of maternal education were all significantly associated with higher PPVT-R scores (for each, P<.001). In addition, early intervention led to greater increases over time in PPVT-R scores among children whose mothers had less than a high school education compared with those with a high school education level or greater (P =.03 by test for interaction). Although most children showed improvement in PPVT-R scores with increasing CA, children with early-onset IVH and subsequent significant central nervous system injury had the lowest PPVT-R scores initially and the scores declined over time (P =.009 by test for interaction).


CONCLUSIONS
The majority of VLBW children had improvement in verbal and IQ test scores over time. Only children with early-onset IVH followed by significant central nervous system injury had low PPVT-R scores that declined over time.
Ment
Laura R
LR
Department of Pediatrics, Yale University School of Medicine, 333 Cedar St, New Haven, Conn 06520, USA. laura.ment@yale.edu
Vohr
Betty
B
Allan
Walter
W
Katz
Karol H
KH
Schneider
Karen C
KC
Westerveld
Michael
M
Duncan
Charles C
CC
Makuch
Robert W
RW
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001925:Brain Damage, Chronic / Q000517:prevention & control; D002543:Cerebral Hemorrhage / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D003071:Cognition; D002658:Developmental Disabilities / Q000453:epidemiology / Q000503:physiopathology*; D005500:Follow-Up Studies; D006801:Humans; D007213:Indomethacin / Q000627:therapeutic use; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development*; D007235:Infant, Premature, Diseases / Q000503:physiopathology* / Q000517:prevention & control; D019102:Infant, Very Low Birth Weight / Q000254:growth & development*; D011581:Psychological Tests; D012959:Socioeconomic Factors
D000894:Anti-Inflammatory Agents, Non-Steroidal; D007213:Indomethacin