NEONATAL SOCIETY ABSTRACTS
Long term cognitive outcomes of infants born at near term
Presented at the Neonatal Society 2010 Summer Meeting (programme).
Odd DE1,2, Emond A3, Whitelaw A1,2
1 Neonatal Unit, Southmead Hospital, Bristol, UK
2 Clinical Science at North Bristol, University of Bristol, Bristol, UK
3 Centre for Child and Adolescent Health, University of Bristol, Bristol, UK
Objective: The long term outcome of infants born at near term gestations is unclear although recent work has suggested increased risk of poor educational performance(1). The aim of the study was to investigate whether infants born at near term (32-36 weeks gestation) have poorer cognitive measures than those born at term.
Methods: This study is based on the Avon Longitudinal Study of Parents and Children (ALSPAC) containing data on over 14,000 infants. Cognitive function was assessed at a half day clinic when study participants were aged 8 years using the WISC-III. Exposure groups were defined as near term (32-36 weeks) or term (37-42 weeks). Linear regression models were used to investigate the association between gestational age group and IQ while a multiple imputation data technique (Chained Equations) was used to impute the missing covariate data. The regression analysis adjusted for any clustering around multiple births using a random effects model. Ethical approval for the study was obtained from the ALSPAC Law and Ethics Committee and the Local Research Ethics Committees.
Results: The main analysis was based on 6,957 infants with summary IQ scores. In the unadjusted model there was only weak evidence that infants born at near term had lower IQ scores than those at term (-1.38 (-3.20 to 0.44)) and this association weakened further after correction for socio-economic factors (-0.88 (-0.54 to 0.78)) and in the fully adjusted model (-0.24 (-1.94 to 1.46)).
Discussion: There is little evidence of a reduction in IQ measures in infants born at near term compared to their peers born at term. A small effect was seen in the unadjusted model, but after correction for potential confounders this weakened further. Further work may identify if a burden of other neuro-pathology exists in these infants.
1. Lindstrom K, Winbladh B, Haglund B, Hjern A. Preterm Infants as Young Adults: A Swedish National Cohort Study. Pediatrics 2007;120:70-7.