Abstract:
Aim The aims of this thesis are to (1) describe growth and neurodevelopmental outcomes of children born at risk of neonatal hypoglycaemia, a common condition that may be associated with adverse neurodevelopmental outcome; (2) investigate methods used for data collection in paediatric longitudinal studies; and (3) determine the relationships between glycaemic response to neonatal hypoglycaemia, its treatment, and later neurodevelopmental outcome. Methods Prospective study of children born at risk of neonatal hypoglycaemia at Waikato hospital (2006-2010), the CHYLD study. Intermittent blood and continuous interstitial glucose concentrations were recorded in the neonatal period. Hypoglycaemia (blood glucose concentration <2.6 mmol/l) was treated with breast milk, formula, dextrose gel, and intravenous dextrose. At 2 and 4.5 years’ corrected age children were assessed for neurodevelopmental and general health status. Caregivers completed questionnaires about the medical history and social-emotional health of their children. Children’s hospital records were accessed and preschool screening data was obtained from the Before School Check programme. Findings Children in our study lived in more deprived areas compared to the national average, and approximately a third had neurosensory impairment at both 2 and 4.5 years. Neurodevelopmental outcomes were not related to neonatal risk factors. We identified problems with several of the methods commonly used for follow-up assessments. Caregivers could not accurately recall previous hospital admissions at the 4.5 year assessment when compared to hospital records. Referral criteria for developmental and emotional health problems were not applied consistently in the Before School Check, and children who had problems often missed out on screening. In addition, assessment of motor function at 2 years was not predictive of motor difficulties at 4.5 years. We found that treatment of neonatal hypoglycaemia was associated with different glycaemic responses in the six hour period after hypoglycaemia, and the rate of change in glucose concentrations was related to later neurodevelopmental outcome. Conclusions Our findings in an at-risk cohort of children with high impairment rates will help researchers and clinicians to plan future studies, draw attention to some limitations of the New Zealand preschool screening programme, and guide future research on treatment of neonatal hypoglycaemia to improve later outcomes.