Objective: This study was part of a geographically defined national study on survival, health, development, and longterm outcome of extremely low birthweight infants (ELBW; birthweight < 1000g) in Iceland focusing on development and neurodevelopmental measures in comparison to a reference group.
Methods: All 35 ELBW longtime survivors born in 1991-95 and 55 children as matched reference group were enrolled in a prospective study on longterm health and development. The children underwent medical examinations and neurodevelopmental testing at five years of age in 1996-2001, and their parents answered a questionnaire on their behavior.