Hypoxic-ischaemic encephalopathy (HIE): the brain deprived of oxygen or blood
Hypoxic-ischaemic encephalopathy (HIE) develops when blood flow that carries oxygen and nutrients to the baby is severely restricted during birth. If sufficiently severe, this condition carries a significant risk of death — or survival with major disability. Currently, there is only one treatment for babies born with moderate to severe HIE: therapeutic hypothermia, but it does not protect every baby. A team of researchers believe they might just have a solution.
A major cause of brain injury and disability
During pregnancy, an unborn baby receives its oxygen and nutrients from blood via the umbilical cord. HIE develops when this blood flow is severely disrupted during birth — restricting the baby’s supply of oxygen (hypoxia) and blood (ischaemia), which damages the baby’s brain (encephalopathy).
This condition is known as moderate-severe HIE, and is a major cause of brain injury in unborn babies, and occurs in around one to three out of every 1000 babies born. In New Zealand, this means that roughly 70 babies will be born each year with HIE.
Babies that develop HIE are at significant risk of death and disability. By the age of 2 years, 40–60% of babies with this condition will have died or survived with a severe disability — such as blindness, hearing loss, or cerebral palsy. Along with the devastating impact to the families of these children, disabilities due to HIE also place significant strain on healthcare and educational resources.
Current treatment options
Therapeutic hypothermia, which involves cooling of the baby’s brain or body, is currently the only recognised treatment for HIE. It works by reducing the extent of the damage to the baby’s brain – but only in best circumstances.
“Therapeutic hypothermia is standard treatment for these infants and improves their outcomes into infancy and childhood,” says Dr Guido Wassink, a Senior Research Fellow at the University of Auckland, “but it is not a silver bullet and it needs to be started within 6 hours of birth for effective protection of the brain. Because of this, additional therapeutic strategies are needed to further reduce disability.”
A major leap forward
Dr Wassink and his team – including researchers from the University of Auckland and Neonatologists from around New Zealand – are investigating whether a growth hormone, called recombinant human erythropoietin, will improve outcomes for babies with HIE when given after therapeutic hypothermia.
“Recombinant human erythropoietin can protect the developing brain,” says Dr Wassink, “and boost brain repair and regeneration after oxygen deprivation. This research will provide key evidence on whether delayed treatment with recombinant human erythropoietin can further improve recovery of the newborn brain after therapeutic hypothermia.”
Recombinant human erythropoietin will first be tested on lambs that have undergone oxygen deprivation. If successful, this promising treatment can then be trialled in babies with HIE. “The most fascinating part of this research,” says Dr Wassink, “is that any baby is far more resilient to periods of low oxygen than you or I. And although very severe oxygen deprivation around birth can have devastating lifelong consequences, the developing brain also generates new brain cells at a much higher rate than adults. If we could develop treatments that exploit this untapped potential to repair the brain — that would be a major leap forward in terms of being able to treat brain-injured newborn babies in the future.”
How you can help
This research was chosen to receive a Project Grant from Cure Kids in 2021 – along with nine other research studies from around Aotearoa New Zealand. It is only through the generous contributions of people like you that Cure Kids can continue to fund vital research – such as the work of Dr Wassink and his team in treating babies with hypoxic-ischaemic encephalopathy.
Cure Kids is committed to enabling research that has the potential to transform the health and wellbeing of our precious tamariki – but we need your help. Find out how you can become a Cure Kids donor today.
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