Follow-up of the newborn cohort continued in order to better understand the severity, onset of early organ damage, and risk factors. Patients were given an entry evaluation consisting of interim history, complete physical examination, complete blood count, urinalysis, blood drawn for haplotype determination and for the serum bank, magnetic resonance imaging of the brain, pulmonary function tests with arterial blood gas, and psychomotor tests. Patients had interim assessments at six months and annual assessments as well as an exit assessment in the fourth or fifth years. The exit assessment was the same as the entry assessment.