Aim: The aim of this study was to identify subgroups of children born moderately preterm (MPT) and term with distinctive levels and patterns of functioning, and the perinatal and demographic factors that predict subgroup membership.
Method: A total of 378 children aged 7 years, 248 MPT (138 males, 110 females; gestational age 32-36 wks) and a comparison group of 130 children born at term (58 males, 72 females; gestational age 38-41 wks), were selected from a community-based cohort study. Latent class analyses were performed on measures of intelligence, verbal memory, attention, executive functioning, and visuomotor and motor skills. χ(2) automatic interaction detection analyses were performed to detect associations between the subgroups and predictors.
Results: Four subgroups differing in levels of performance were identified, with parental education being the only statistically significant determinant of subgroup assignment (p < 0.01). The subgroup that performed the most poorly showed an irregular pattern of performance, with specific weakness in attentional skill and relative strength in intelligence and verbal memory. Parental education predicted classification probability in the preterm group (p = 0.04) but not in the term group (p = 0.15).
Interpretation: Our results show that the poorer performance of children born MPT reflects a higher proportion of children with below average performance rather than a subgroup with extremely poor performance. They indicate that MPT birth affects neurodevelopmental functioning at early school age only slightly, with effects being largest in such children with low parental education.
© The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.