Medicine, University Medical

Objective To compare preschool children born moderately preterm (MP; 32–35 weeks ’ gestation) and children born at term (38–41 weeks ’ gestation) regarding the occurrence of behavioural and emotional problems, overall, for separate types of problems and by gender. Design Prospective cohort study consisting of a community-based sample of MP and a random sample of term-born children in 13 Preventive Child Healthcare centres throughout the Netherlands. Patients 995 MP and 577 term-born children just under age 4 were included. Main outcome measures Behavioural and emotional problems were measured using the Child Behavior Checklist 1.5–5 years. Seven syndrome scales, internalising, externalising and total problems were determined. Higher scores indicate worse outcomes. Results MP children had higher scores on all syndrome scales, internalising, externalising and total problems than term-born controls. The mean difference on total problems was 4.04 (95 % CI 2.08 to 6.00). Prevalence rates of elevated externalising problem scores were highest in boys (10.5%) and internalising problems were highest in girls (9.9%). MP children were at greater ris