89: Influence of Socioeconomic Status on Neurodevelopmental Outcomes in Very Preterm Infants, in the Canadian Context

Abstract

BACKGROUND: Preterm birth is more common and on the rise in populations with low socioeconomic status (SES). The combined risk from preterm birth and SES has been coined as 'double jeopardy' referring to the cumulative effects that biological and social factors have on early infant development. OBJECTIVE(S): To determine if low SES in very preterm infants in a defined urban population is associated with death or neurodevelopmental impairment (NDI) at 18 months adjusted age and 36 months. DESIGN/METHODS: We used the deprivation index from the Canadian Population Health Initiative (CPHI) to classify our population based on postal code at the time of birth. Infants born less than 29 weeks gestation, born from 2008-2011 and residing in a major Canadian urban centre were included in this study. Infants with major congenital anomalies were excluded. Birth postal code information and maternal/neonatal characteristics were obtained from a Neonatal Database. Follow-up information was obtained from a Neonatal Follow-up Database. NDI assessed at 18 months adjusted and 36 months were defined as either a severe or moderate disability. Severe Disability included one or more of the following: non-ambulatory cerebral palsy (CP), Gross Motor Functional Classification System (GMFCS) level 3-5, cognitive composite score less than 55, 3 SD below the mean, legal blindness <20/200, bilateral sensorineural hearing loss (SNHL) or two or more moderate disabilities. Moderate Disability included one of more of the following: ambulatory CP, GMFCS level 1-2, cognitive composite score 55-69, less than 2 SD but greater than 3 SD below the mean, visual impairment <20/60, unilateral SNHL. RESULT(S): There were 258 infants who met criteria for the study. At 18 months adjusted the association between low SES and death or NDI at 18 months was OR=2.52 (95% CI 1.32-4.85). This means that in comparison with infants born to average/high SES were at 2 1/2 times the odds of having either died or being disabled by the age of 18 months. In our evaluation of survivors we found no statistically significant association between SES and moderate/severe NDI, although there was a trend towards an association. There was no significant difference in survival or major neonatal morbidities between low and average/high SES groups. CONCLUSION(S): In our urban centre, SES is associated with death or moderate/severe NDI at 18 months adjusted age in infants born less than 29 weeks. More long-term follow up is required to determine if this association persists. Our study is limited by its small sample size and the low incidence of neurodevelopmental impairment.