Background: In a national Norwegian cohort of children born before 28 weeks gestation or with a birth weight less than 1000 g born in 1999 and 2000, 372 survived. Compared with earlier studies survival increased for the most immature infants, but at the cost of more early complications and a high rate of impairments, while the less immature children had fewer early complications and less impairments detectable within 5 years. These changes show the importance of monitoring outcome as treatment modalities change. Large brain haemorrhages were highly predictive of severe disabilities, but we have not found good predictive factors for milder impairments such as cognitive, behavioural and motor difficulties. However, at 5 years later function may be difficult to predict, and the children's potentials are better understood after completing several years in school. Objectives: The children will be re-examined at age 11 in order to assess their physical and mental health, and cognitive, motor and social function, and to determine if early life events and development at 2 and 5 years are predictive of long term health and functioning. MRI-studies, including functional MRI will be performed to examine if different outcomes related to brain function can be explained by differences in brain development. Methods: For all, data will be collected from the compulsory national test in 5th grade and questionnaires to the child, parents and teacher. For children in Western Norway (n=87) extensive examinations of lung and brain function, including clinical diagnostic tests and MRI, will be added. For all aspects of the study the investigators have appropriate current and historic reference populations for comparison. Implications: Knowledge on causes and of early predictions of outcome is needed to give appropriate advice to families, professionals and society, and to develop preventive programs.

Questionnaires to parents: On general and neurosensory developmental Health (spesific questionnaire for the study) and pulmonary health (ISAAC-questionnaire). Mental Health and social functioning: Strengths and Difficulties (SDQ) questionnaire (also completed by Teachers), ASSQ and BRIEF.

Addtions for children born in the Western Norway Regional Health Authority:

All the children (n=52) and matched Controls born at term have measurements of height, weight and blood pressures, pulminary function tests, MRI and functional MRI of the brain, Assessment of bone mineralization and distribution of fat and muscle (DXA). Blood is collected in a biobank for assessment of inflammatory variables.

Inclusion Criteria:

• Born in 1999 and 2000 with gestational age < 28 weeks or birth weight < 1000 g
• still living when 11 years old

Exclusion Criteria:

• None

All extremely preterm infants (gestational age < 28 weeks or birth weight < 1000 g born in Norway in 1999 and 2000 and still living at age 11 years. Postal survey on outcome. In addition a subgroup (80 out of 365)living in Western Norway will be examined with respect to general health, lung function, mental development, quality of life and cerebral imaging (fMRI)