Objective: Survival of extremely low birthweight infants (BW<1000g) in Iceland has increased in recent years, especially since the availability of surfactant therapy for Respiratory Distress Syndrome of Prematurity. This study was part of a geographically defined national study on survival, health, development and longterm outcome of extremely low birthweight (ELBW) infants in Iceland focusing on health, development and disabilities with reference to a control group.
Material and methods: Information from the National Birth Registry on births in Iceland of ELBW infants weighing 500-999g was collected in two periods 1982-90 and 1991-95, before and after surfactant therapy became available. Information on pregnancy, birth, diseases in the newborn period and later health problems was collected from hospital records. The ELBW infants born in 1991-95 and matched control children were enrolled to a prospective study on longterm health and development. The children undervent medical examinations and developmental testing at 5 years of age in 1996-2001. Comparison was made between the two groups of ELBW infants and between ELBW infants and control children born in 1991-95.
Results: In 1982-90 the longterm survival of ELBW infants at 5 years of age was 22% and 52% in 1991-95. In both periods 1982-90 and 1991-95 similar data was found on ELBW infants regarding mothers health, pregnancy, birth and neonatal period. Difference was found in maternal age being significantly higher (p=0.02) and significally more deliveries by cesarian section (p=0.02) in the latter period. The two groups of ELBW infants were similar regarding sex, birthweight and diseases in the newborn period. Comparison between 35 ELBW infants and 55 control children born 1991-95 showed that significantly more mothers of ELBW children smoked during pregnancy (p=0.003) and suffered from various diseases (p=0.001). More ELBW children were born by cesarian section (p=0.001) than control children and their parents reported more longterm health problems regarding astma (p=0.001), convulsions (p=0.001), difficulties in swallowing (p=0.001) and weight gaining (p=0.005). At five years of age significantly more ELBW children born in 1991-95 compared to control children had abnormal general physical examination (p</=0.001), neurological examination (p</=0.001) and motor skills (p</=0.001). Scores on developmental testing were significantly lower (p=0.002). The proportion of ELBW children with disabilities was 16% in 1982-90 and 14% in 1991-95.
Conclusions: The two groups of ELBW infants born in 1982-90 and 1991-95 are similar regarding problems during pregnancy, birth and newborn period. The proportion of children with disabilities is similar in both periods although survival was significantly increased. When compared to matched control children, ELBW children born in 1991-95 suffer significantly more longterm health and developmental problems.