The New Zealand 1986 very low birth weight cohort as young adults: mapping the road ahead.

BACKGROUND: Very low birth weight (less than 1500 g) is associated with increased morbidity and costs of health care in childhood. Emerging evidence suggests these infants face a range of health and social problems as young adults. We studied all New Zealand very low birth weight infants born in 1986 (when 58% were exposed to antenatal corticosteroids) in infancy, with later follow-up at 7 to 8 years and 23 to 24 years. We now aim to assess the cohort at 26-28 years compared with controls.

METHODS/DESIGN: The case sample will comprise a minimum of 250 members of the 1986 New Zealand national very low birth weight cohort (77% of survivors). Outcomes will be compared with a control group of 100 young adults born at term in 1986. Following written informed consent, participants will travel to Christchurch for 2 days of assessments undertaken by experienced staff. Medical assessments include growth measures, vision, respiratory function, blood pressure and echocardiogram, renal function, dental examination and blood tests. Cognitive and neuropsychological functioning will be assessed with standard tests, and mental health and social functioning by participant interview. A telephone interview will be conducted with a parent or significant other person nominated by the respondent to gain a further perspective on the young person's health and functioning. All those born at less than 28 weeks' gestation, plus a random subset of the cohort to a total of 150 cases and 50 controls, will be offered cranial magnetic-resonance imaging. Statistical analysis will examine comparison with controls and long-term trajectories for the very low birth weight cohort.

DISCUSSION: The research will provide crucial New Zealand data on the young adult outcomes for very low birth weight infants and address gaps in the international literature, particularly regarding cardiovascular, respiratory, visual and neurocognitive outcomes. These data will inform future neonatal care, provide evidence-based guidelines for care of preterm graduates transitioning to adult care, and help shape health education and social policies for this high risk group.

TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12612000995875 . Registered 1 October 2012.