In this follow-up study of school-aged children who were premature infants with RDS and treated with surfactant-replacement therapy, we used historical, physical, and neurodevelopmental assessments to measure readiness for entry into public school and the risk factors determining lack of school readiness. Male gender, CLD, and severe IVH/PVL, factors well-known to predispose to abnormal neurodevelopment, constituted risks for lower school-readiness levels. However, decreased socioeconomic class constituted the strongest barrier to achieving school readiness.
Assessing intercenter differences in neurodevelopmental outcome of extremely low birth weight premature infants at 18 to 22 months of age, Vohr et al46
found that the use of postnatal steroids and increased duration of mechanical ventilation increased rates of neurodevelopmental impairment. We also found that longer duration of ventilatory support was associated with decreased school-readiness levels. However, after adjusting for CLD in a multivariate analysis, duration of ventilatory support was not an independent risk factor. In addition, having a prolonged postnatal dexamethasone course was not associated with lack of school readiness. However, the small number of children receiving prolonged postnatal steroids (15 of 135 infants) is likely too small to detect significant differences.
A child’s readiness for school requires age-appropriate physical, behavioral, communicative, visual, motor, and conceptual skills. Accordingly, in designing our assessment of school readiness, we used a multidimensional battery of well-validated cognitive, language visual-motor, functional, and behavioral assessments, supplemented with diagnoses of CP and sensory impairment, to assign school-readiness levels. Children scoring between 1 and 2 SDs below the mean on ≤2 measures (level 3) have been considered to have minor impairments and may need special education services.17
Accordingly, we considered these children ready for school but at an increased disadvantage compared with their peers. Children unable to perform better than 2 SDs below the mean in any of the measures employed (level 2), as well as those having significant sensory or motor impairment (level 1), clearly cannot participate in the regular classroom.
Neurodevelopmental follow-up studies of preterm infants at school age have used full-scale IQ scores or disability diagnoses (CP, blindness, deafness) as primary outcome variables.15,47,48
However, preterm infants are at increased risk for learning disabilities,45
which by current definition occur in the setting of normal IQ scores.49,50
Children having learning disabilities require special education services,51
and these needs will not be identified by standard IQ assessments alone. A school-readiness evaluation, such as ours, that assesses performance in these domains more completely describes a child’s overall learning ability. Our assessment distinguishes important, subtle, functional delays leading to poor school performance. Future long-term neurodevelopmental follow-up studies may benefit from adding multidimensional school-readiness evaluations to standard assessments of IQ and disability.
The ability to perform MRI in premature children has allowed for a better understanding of brain development and the potential contribution to long-term adverse outcome in this vulnerable population. By using MRI, Peterson52
measured regional brain volumes in 8-year-old children who were preterm and term infants who had their IQ measured. In the brain regions of preterm infants where the greatest abnormalities in regional brain volumes were observed, the degree of abnormality correlated with IQ,52
suggesting a contribution of morphologic abnormality to functional outcome. It is conceivable that school-readiness levels correlate similarly with regional brain volume abnormalities.
By using functional MRI, Ment et al53
demonstrated that, at 8 years of age, preterm boys who received indomethacin in the NICU may demonstrate improved phonologic processing compared with saline-treated boys, and comparable with boys born at term. In our study, all infants with birth weights <1250 g received prophylactic indomethacin. To the extent that this subtle improvement in linguistic processing may improve performance on the school-readiness tests we employed, school-readiness levels of those males in our study who received prophylactic indomethacin may have been improved. However, the profound effects we observed of low socioeconomic status on school readiness are likely to dwarf any possibly beneficial effect of indomethacin.
A school-readiness measure has, to our knowledge, been employed in only 1 previous study, in which risk factors associated with need for special education services in kindergarten were assessed in premature infants (23–28 weeks’ gestation).17
This retrospective cohort study defined kindergarten-readiness as having no major impairments or no more than 1 minor impairment. In this population, only 35% of children were considered kindergarten-ready, consistent with the study being performed before the routine use of surfactant and antenatal steroids. Interestingly, neither IVH nor CLD was found to be a significant risk factor for lack of kindergarten readiness. Nonetheless, socioeconomic class was found to be as powerful a predictor of lack of kindergarten-readiness as in the present population.
We found that the strongest risk for decreased school-readiness levels was low socioeconomic status. Although where a child received early intervention was independent of socioeconomic status, it is unclear whether the detrimental effect of socioeconomic status is related to the quality of early intervention received or the social milieu of impoverished families. Impoverished families are at higher risk for parents with decreased education,31,54–59
having a single parent household,58,60
having decreased access to resources,60–62
and increased psychological distress.66,67
These factors likely contribute to impoverished environments for child development, including a low stimulation environment,68,69
impoverished oral language exposure,57,60,68
and decreased exposure to cognitively stimulating materials,62,67,70
factors potentially affecting neurodevelopmental outcome. To the extent that families in our study in the lowest socioeconomic stratum are similarly at risk, our data demonstrate that this social environment conspires to retard cognitive and functional development to a far greater extent than physical morbidities acquired as a result of prematurity or its complications.
We found that 33% of school-aged children born prematurely with RDS were, in fact, not ready for school and 15%, although ready, were at risk for needing special education. How do these statistics compare to the general population? To our knowledge, no information is systematically compiled by public school districts on school readiness of children entering kindergarten. Therefore, a direct comparison of our cohort with the general population is not possible. Similarly, without a term control group matched for socioeconomic status, we are unable to assess whether decreased socioeconomic status plays as significant a role in determining school readiness in term infants.