What is Hypoxic-Ischaemic Encephalopathy (HIE)?

Initiated by the charity Peeps, HIE Awareness Day is held annually on April 4th. This day aims to raise awareness of these injuries and supporting families. This article shares:  

• What is hypoxic ischemic encephalopathy 

• The cause of hypoxic ischemic encephalopathy  

• How a diagnosis is reached  

• Immediate treatment  

• Longterm outcomes of hypoxic ischemic encephalopathy  

• What support is available for parents and families 
• Hypoxic ischemic encephalopathy medical negligence 

What is Hypoxic-Ischaemic Encephalopathy (HIE)?  

Hypoxic-Ischaemic Encephalopathy (HIE) is a brain injury caused by a lack of oxygen or blood flow around the time of a baby’s birth. Effecting 1-3 babies in every 1000 within the UK, this medical emergency requires a quick diagnosis and immediate treatment.  

In the immediate moments of lack of oxygen, brain cells lose energy and become damaged, potentially leading to those cells dying due to a lack of nutrients. As well as this, when blood flow returns, further damage can occur from inflammation and toxins released by injured cells.

What causes HIE?  

Any event that interrupts the baby’s oxygen supply before, during or after birth from the placenta or cord can lead to Hypoxic-Ischaemic Encephalopathy (HIE) in a baby. 

There are a number of situations where this interruption to oxygen supply may arise, including:  

• Delayed C-section  

• Umbilical cord issues such as entanglement or compression 

• Problems with the placenta, including reduced function or premature separation 

• Failure to monitor foetal distress and respond in a timely manner

Immediate action in these cases is vital. If foetal distress is detected but delivery is not expedited, oxygen deprivation can worsen. A prolonged or difficult labour can also cause a reduce oxygen supply. When foetal distress is identified, prompt delivery is often necessary to prevent ongoing oxygen deprivation.  

How is HIE Diagnosed and Graded?  

These injuries are diagnosed through a combination of clinical examination and specialist tests soon after birth. Doctors begin by assessing the newborn baby’s:  

• Alertness 

• Muscle tone  

• Reflexes 

• Breathing 

• Whether seizures are present 

These are key neurological signs that help identify early brain injury. This examination forms the basis of grading HIE into mild, moderate, or severe, a system widely used in neonatal care to guide treatment and predict outcomes.  

To understand the extent of brain involvement, medical professionals use tools such as EEG or aEEG monitoring, which track the brain’s activity and help detect abnormal patterns or seizures. MRI scans are also an important part of the assessment, offering detailed images that can show specific areas of the brain affected by oxygen loss.  

In addition to these tools, blood tests can help identify how severely the baby was impacted during the birth event. Together, these tools provide a full picture that helps the medical team make informed decisions and offer parents clear guidance and reassurance about the next steps.

Immediate Treatment: Cooling Therapy and Emergency Care  

When a baby is diagnosed with a moderate or severe HIE birth injury, the most important immediate treatment is therapeutic hypothermia, also known as cooling therapy. This is a highly specialised treatment where the baby’s body temperature is gently lowered to around 33.5°C and kept at that level for 72 hours to help protect the brain from further injury. Cooling must begin as soon as possible and ideally within the first 6 hours after birth; this early window offers the best chance of reducing long‑term damage.  

Not all babies are eligible as cooling therapy is typically offered to infants who are ≥36 weeks gestation and show clear signs of moderate or severe encephalopathy based on criteria assessed by senior neonatal specialists.  

During treatment, babies are cared for in a neonatal intensive care unit where their temperature, heart rate, breathing, brain activity, and blood results are closely monitored to keep them safe and supported throughout the cooling and gradual re‑warming process.

Long-Term Outcomes and Development 

The long‑term outlook for babies with Hypoxic‑Ischaemic Encephalopathy (HIE) is different between each child and depends largely on the severity of the initial brain injury. Many babies with mild HIE make a full recovery, with no long‑term effects once the early symptoms settle. However, in cases of moderate or severe HIE, children may face ongoing challenges.  In our experience, we have seen that HIE can lead to several challenges as children grow such as:  

• Developmental delays 

• Learning difficulties 

• Epilepsy  

• Cerebral palsy 

Some difficulties only becoming clear months or even years after the fact as movement and communication skills develop. Because of this, early intervention is one of the most powerful tools for improving long‑term outcomes. Babies and children may benefit from a range of therapies, including: 

• Physiotherapy – to support motor development, strength and mobility. 

• Speech & language therapy – to assist with communication, feeding and early language development. 

• Occupational therapy – to help build everyday life skills. 

• Neurodevelopmental follow‑up – regular assessments to monitor progress and identify challenges as early as possible.

While medical teams focus on clinical care, your legal team plays an important role in ensuring your child receives these treatments and the long‑term support they deserve. If investigation shows that avoidable delays, errors or poor monitoring contributed to the oxygen deprivation, a legal claim for this negligence can secure funding for lifelong therapies. Physiotherapy, speech therapy, occupational therapy and specialist equipment can be costly so a successful claim can ensure your child has uninterrupted access to the interventions that make the biggest difference. 

As well as providing financial stability for care needs, a successful legal claim can bring peace of mind about the structure of your child’s care. As part of the claim, our specialist team can establish provisions for regular assessments and reviews, ensuring your child’s progress is continually supported. 

Support for Parents and Families 

Facing a diagnosis of Hypoxic‑Ischaemic Encephalopathy (HIE) can feel overwhelming, and it’s completely natural for parents to experience shock and uncertainty about the future.  

Hospitals and neonatal teams understand this, and they work hard to support families not only medically but emotionally too. You should feel encouraged to ask questions at any time and to seek explanations more than once if needed. This is a confusing and emotional period, and clear communication is essential.  

There are several resources available to parents both within and outside of the NHS, including:  

• Peeps HIE: A dedicated UK charity that supports families affected by HIE.  

• Patient Advice and Liaison Service (PALS)  

• NHS Talking Therapies (IAPT) 

• Bliss: A charity supporting families with babies born sick or premature, offering support via email ([email protected]) and volunteer video calls.

When Could HIE Be Caused by Medical Negligence? 

No one wants to believe that such severe injuries to their child could be caused by negligent medical care but unfortunately it is possible. HIE can be caused by medical negligence when avoidable delays or errors lead to prolonged oxygen deprivation, such as when clinicians fail to properly monitor or respond to foetal distress during labour.  

When a necessary emergency delivery is delayed, despite known dangers from complications that can critically interrupt oxygen supply, this negligence can severely impact that baby’s whole life and the life of their family.  

Negligence could be present in a delay of treatment after birth such as when a baby with suspected moderate or severe HIE does not receive cooling therapy within the essential 6‑hour window, or experiences delays in being transferred to a cooling-capable unit.  

Seeking legal advice if you think your child has suffered due to medical negligence is essential. Our experts can help explain what has happened and identify if there was negligence care and when the negligence occurred.

Can You Make a Claim for HIE? 

If your child has been diagnosed with Hypoxic‑Ischaemic Encephalopathy (HIE), you may be feeling uncertain about making a claim and what that entails.  

Parents can usually make a claim for Hypoxic‑Ischaemic Encephalopathy (HIE) on behalf of their child if there is evidence that substandard medical care contributed to the oxygen deprivation that caused the injury.  

A successful claim can secure compensation to cover:  

• Lifelong care costs 

• Therapy and rehabilitation 

• Specialist equipment 

• Home adaptations  

• Educational support  

• Loss of future earnings 

For children, the time limit for bringing a claim doesn’t start from the date of the injury. It only begins on their 18th birthday, but only if they have the mental capacity to make legal decisions. If they never gain mental capacity, the time limit doesn’t start at all, meaning a claim can be brought at any time.

Speak to a Specialist HIE Solicitor 

Speaking to a specialist HIE solicitor can help you understand your options with clarity and compassion. There is no obligation to start a claim after an initial conversation and your enquiry will be handled with sensitivity, guided by experts who understand both the medical and emotional complexities of HIE.  

We believe that every birth, every baby and every family deserves answers when maternity care goes wrong. Our award-winning birth injury team is on hand to guide you when you need us most. To speak to an expert today, contact us here.