The long-term effects associated with being born very preterm

A follow-up of a national birth cohort from 1986.

Professor Brian Darlow
University of Otago, Christchurch

What is the problem and who does it affect?

Infants born very low birth weight or very preterm account for about two per cent of births, however, the medical resources expended on them are vastly disproportionate to their prevalence.

Medical advances have meant that more and more of these babies are surviving, however we are now learning that there may well be long-term health and developmental consequences that are a result of prematurity or low birthweight and the necessary neonatal care. Understanding the overall impacts will help with management as well as inform current and future neonatal care.

A population-based cohort of these babies from 1986 provides a rich source of data with which to compare to age-matched controls and elicit critical information about the development of these once vulnerable babies.


What is the research hoping to achieve?

The study began all those years ago with the aim of assessing the incidence of retinopathy of prematurity – the abnormal development of the blood vessels in a preterm baby’s eyes that can result in visual impairment or blindness. Now, at 29-30 years-of-age, they are being followed up again to find out if there any ongoing or newly developing health challenges that could be related to their prematurity at birth.

Prof Brian Darlow is the Cure Kids Chair of Paediatric Research at the University of Otago, Christchurch. He and his team will assess a broad range of health and developmental issues including; vision, blood pressure, growth measures (total body fat), respiratory function, as well as conducting cognitive and neurological functioning assessments.

They have recruited 250 of the original participants as well as 100 age-matched controls (also, born at term and within normal weight parameters). They are assessing on average 3 participants a week and as of August 2016, have fewer than 10 more   to see.

One-hundred of the VLBW cohort, including all those born earlier than 28 weeks, together with 50 controls, will undergo magnetic resonance imaging (MRI) of the brain. The MRIs should give information about alterations in white matter development (the connective matrix of the brain) as well as growth in different areas of the brain, which may then be related to functioning on everyday tasks.

There exist large gaps in both New Zealand and international data with respect to the health outcomes of young adults born very prematurely. The study results will inform future neonatal care, provide evidenced-based guidelines for care of very low birthweight graduates transitioning into adult care, while also helping shape health, education and social policies for this at risk group.

As a greater number of very low birthweight and very preterm babies survive, this research becomes of greater significance to their future health outcomes.