Cognitive outcomes up to age 11 years following preterm birth
Maria Quigley (NPEU)
Child health and development
While children born very preterm (gestation <32 weeks) have an increased risk of cognitive impairment compared to full-term children (39-41 weeks), the risk for children born moderately (32-33 weeks) to late preterm (34-36 weeks) and early term (37-38 weeks) is unclear.
This study describes the relationship between gestational age and cognitive outcomes at 11 years and the trajectory of deficits in verbal ability from age 3-11 years.
Cognitive ability was assessed using the Cambridge Neuropsychological Test Automated
Working Battery (n=11,395) and British Abilities Scale Verbal Similarities test (n=11,889) in the UK Millennium Cohort Study.
Each gestational group was compared with the full-term group using differences in z-scores and odds ratios for delay (scoring ≥1 SD below the mean).
‘Persistent delay’ in verbal skills was defined as delay at ≥2 surveys at age 3-11 years.
Late preterm and early term birth were not significantly associated with working memory or verbal ability at 11 years.
Very and moderately preterm children demonstrated significantly lower working memory z-scores compared to full-term children (adjusted difference -0.2 to -0.6) and were more likely to be delayed, but there was no effect on verbal ability at age 11.
The absence of delayed verbal skills at 11 years in very preterm children, despite delays at younger ages, suggests potential ‘catch-up’ effects.