Introduction:
Extremely low birth weight (ELBW) children (birth weight ≤1000 g) are at risk of adverse neurodevelopmental outcome. The objectives of this study were to determine the prevalence of developmental disorders and disabilities among ELBW children born in Iceland during a 25 year period and to assess which clinical factors predict disability among these children.

Material and methods:
A retrospective study of all ELBW children born in Iceland 1988-2012 and discharged alive. The study group was found in the Children´s Hospital of Iceland NICU registry. Information was gathered from the NICU registry, the children´s and their mothers´ medical records and the State Diagnostic and Counselling Centre database.

Results:
Of 189 children 45 (24%) had developmental disorders, 13 (7%) had mild disorders and 32 (17%) had major disorders (disability) at 3-6 years. Risk factors for disability were multiple birth (RR 2.21; 95% CI: 1.19-4.09), Apgar < 5 after one minute (RR 2.40; 95% CI: 1.14-5.07), the initiation of enteral feeding more than four days after birth (RR 2.14; 95% CI: 1.11-4.11), full enteral feeding achieved after more then 21 days (RR 2.15; 95% CI: 1.11-4.15), neonatal pneumonia (RR 3.61; 95% CI: 1.98-6.57) and PVL (RR 4.84; 95% CI: 2.81-8.34).

Conclusion:
The majority of ELBW children do not have major developmental disorders. The rate of disability in this study is similar to other studies. The study probably underestimates the rate of mild developmental disorders in the Icelandic population. Risk factors for disability in this study are comparable to previous studies.

Table I . Clinical data that was registered regarding the children and their mothers.

Table II . ICD-10 diagnosis in ELBW (birth weight < 1000 g) children with disability born in Iceland 1988-2012.

Table III . Clinical factors and disability.

Figure I. Overview of ELBW infants born in Iceland 1988-2012.

The flowchart demonstrates division of ELBW infants with regard to developmental outcome.

The data is presented as number of children and proportion (%) of the total where n =189

SDCC: The State Diagnostic and Counselling Centre