[P2-154] Intellectual Outcomes of Extremely Preterm Infants at School Age
[Introduction]The survival rate of extremely preterm (EP) infants (<28 weeks of gestation) has improved dramatically, and there is great interest in their long-term prognoses. This study aims to elucidate the influence of prenatal and postnatal care on long-term intellectual outcomes in EP infants. [Methodology]Subjects were EP infants who were admitted to the neonatal intensive care unit of our hospital from 1982 to 2005. The survival rate and neurodevelopmental outcomes at 6 years of age were analyzed for the periods of 1982–1991 (period 1) and 1992–2005 (period 2). Logistic regression analysis was performed to examine risk factors for intellectual impairment (intelligence quotient score <70 or delay as judged by physicians). [Results]Survival rates improved significantly from 84.5% (period 1) to 92.4% (period 2) (p = 0.007). Follow-up data were obtained from 92 (69.7% of survivors, period 1) and 245 (72.3% of survivors, period 2) children. The incidence of intellectual impairment increased from 16.3% (period 1) to 31.0% (period 2). Significant factors associated with intellectual impairment were period 2 [odds ratio (OR) 3.53, p = 0.007], supplemental oxygen at 36 weeks corrected age (OR 2.22, p = 0.012), number of days in the hospital (OR 1.01, p = 0.012), intraventricular hemorrhage (OR 3.05, p = 0.024), and later tube-feeding commencement date (OR 1.10, p = 0.032). [Conclusions]These results suggest that reducing the incidences of chronic lung disease and/or apnea, intraventricular hemorrhage, and nutritional deprivation is a key factor in improving the intellectual outcomes of EP infants.