Cognitive status, language attainment, and prereading skills of 6-year-old very preterm children and their peers: the Bavarian Longitudinal Study.

The prevalence of intellectual-, language-, and prereading-skill deficits was investigated in a geographically defined whole-population sample of very preterm children at 6 years of age in southern Germany. The sample consisted of the following: 264 very preterm children (75.6% of German-speaking survivors); 264 term controls (matched for sex, socioeconomic status [SES], marital status and age of mother); and a representative normative sample for Bavaria (N=311). Compared with term peers, very preterm children scored significantly lower (approximately -1SD) on the measures of cognitive and language skills and had major cognitive deficits (<-2 SD) 10 to 35 times more often than the controls. Deficits in speech articulation and prereading skills (<l0th centile) were three to five times more frequent in very preterm children. More than 18% of very preterm children had cognitive deficits in more than five areas of functioning, compared with no control children. The differences between very preterm children and controls remained highly significant when only very preterm children (N= 229) and controls (N= 261) without major neurosensory impairment were considered. Little evidence for specific cognitive deficits was found once mental processing measured in the Kaufman Assessment Battery for Children (K-ABC) was controlled for. The effect of preterm birth on cognitive abilities was found to be larger than the influence of SES. In conclusion, there was a high prevalence of long-term multiple cognitive problems in very preterm children. These persistent cognitive problems appear to be of pre- or neonatal (treatment) rather than postnatal social origin.