Long-term follow-up of very low birthweight children : A prospective study from the southeast region of Sweden
Abstract: Background: The survival rates for very low birthweight (VLBW; birthweight ≤1500 g) children are increasing, but they run a greater risk than controls of developing neurosensory disabilities and other functional problems during childhood. However, there is a great need for more knowledge regarding long-term outcome to adulthood in VLBW subjects.Aims: To evaluate long-term outcomes in a regional cohort of VLBW children born in 1987-88 regarding hospital readmissions, morbidity, neurological conditions, cognitive function, reading skills, school achievements, behaviour, growth, general health, and social functioning in relation to gender, neonatal risk factors, disability and Magnetic Resonance Imaging (MRI) findings.Study design: Prospective longitudinal case-controlled long-term regional follow-up.Material and Methods: A total of 86 (80.4%) children (47 boys out of 60 and 39 girls out of 47 live-borns) survived the neonatal period and were recruited to the follow-up study. A total of 86 term controls (45 boys and 41 girls) were included from the newborn period. Readmissions, hospital diagnoses, need of habilitation and child psychiatric care were checked in registers to 15 years of age. The VLBW children were enrolled in the follow-up study at 40 weeks gestational age and at 4, 9, and 15 years of age in assessing neurological conditions. At 15 years of age, the groups were assessed in cognition (WISC III), reading skills, school outcome, behaviour, vision and growth. Fifty-nine (69%) VLBW children were examined using cerebral MRI. Physical and mental health, weight and height, education, and socio-economic situation were assessed at 20 years of age in 77/85 VLBW and 69/84 control subjects by means of postal questionnaires.Results: VLBW boys had three times more readmissions compared with control boys (p=0.003). Gestational age below 30 weeks, birthweight less than 1000 g, and mechanical ventilation were neonatal risk factors for readmissions. Five (5.8%) children had moderate/severe cerebral palsy, 5 (5.8%) had attention deficit hyperactivity disorder, and 1 was blind due to retinopathy of prematurity.VLBW children were inferior in neurological function in comparison with controls at 40 weeks of gestational age and 4 and 15 years of age. Fourteen of 56 (25%) VLBW children without overt disability had abnormal MRI findings. Mechanical and/or intraventricular haemorrhages (IVH) were significantly related to less favourable neurological outcome. VLBW children performed significantly lower than their controls on a few reading variables and on WISC III. Half of them had IQ lower than 85. Ten VLBW children with IQ < 70 had not been clinically identified earlier and a majority of these children attended mainstream school. Small head circumference correlated with low IQ. Mechanical ventilation and IVH correlated with lower IQ and poorer reading skills. At 20 years of age, the VLBW subjects did not differ significantly from the controls in self-perceived health, education, occupation and way of living.Conclusions: Most VLBW subjects were without major health problems up to 20 years of age and had attended mainstream schools. The presence of IVH and mechanical ventilation during the neonatal period negatively influenced health outcomes. VLBW children without overt neurological disability performed somewhat less well in neurological examinations in comparison with controls. VLBW children achieved poorer results in cognitive tests, but reading skills made a catch-up to 15 years of age. A majority of VLBW subjects managed transition to adulthood similar to that of controls.
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