Description of the cohort of children born EP or with ELBW (gestational age 22–27 weeks or birth weight 500–999 g) in Norway in 1999 to 2000 and assessed for mental health follow-up at 11 years of age. Description of the cohort of children born EP or with ELBW (gestational age 22–27 weeks or birth weight 500–999 g) in Norway in 1999 to 2000 and assessed for mental health follow-up at 11 years of age. Severe CP defined as class 4 to 5 according the GMFCP; IQ according to the Wechsler Preschool and Primary Scale of Intelligence-Revised. SIDS, sudden infant death syndrome. Silje Katrine Elgen Fevang et al. Pediatrics 2016;137:e20153002 ©2016 by American Academy of Pediatrics