What is hypoxic ischemic encephalopathy in babies?
Hypoxic ischemic encephalopathy is a type of brain damage that can occur when a baby’s oxygen and blood supply drop around the time of birth.
HIE is usually diagnosed shortly after delivery, often in the NICU, when a newborn needs help breathing, has seizures, or requires cooling treatment after a difficult labor. Doctors may describe the injury as mild, moderate, or severe, but it can take time to see how a child is affected.
HIE in babies can result in mild delays to lifelong conditions like cerebral palsy. Early on, it is not always clear what the future will look like.
Hypoxic ischemic encephalopathy is often linked to complications during pregnancy or delivery. In some situations, delivery teams may not respond quickly enough to signs of fetal distress or oxygen loss. When that happens, it may be considered medical negligence.
If your baby was diagnosed with HIE, you may have left the hospital scared and without clear answers about what comes next. Cerebral Palsy Guide has labor and delivery nurses on staff who are here to help. Our registered nurses have decades of combined experience.
If you have questions, connect with a nurse right now. It’s always free to talk with our team.
Quick facts on HIE
- About 1 to 6 out of every 1,000 babies are affected. In the U.S., that adds up to about 9,000 to 12,000 babies each year, according to Cleveland Clinic.
- Hypoxic ischemic encephalopathy is a medical emergency. Babies with possible HIE need fast treatment to protect the brain.
- Around 25–60% develop conditions such as cerebral palsy, epilepsy, or learning problems.
- Severe HIE can be fatal. About 20–50% of affected infants do not survive.
- Some problems show up later. Developmental delays, learning issues, or movement problems may not be clear until months or even years later.
- Cooling therapy is the main treatment. Doctors may cool the baby’s body for a short time after birth. This can lower the risk of death and severe disability if started quickly.
Early signs of HIE in newborn babies
Symptoms of hypoxic ischemic encephalopathy are not always obvious in the first hours of life. If there were concerns during delivery, medical teams may watch carefully for signs of hypoxia in newborns before determining how serious a possible birth injury may be.
Common warning signs can include:
- Breathing problems
- Decreased alertness or hard to wake
- Feeding trouble
- Floppy or weak muscle tone
- Pale or blue skin or lips
- Seizures or unusual jerking
- Slow or absent reflexes
- Weak cry
Some babies with hypoxic ischemic encephalopathy have a low Apgar score right after birth. The Apgar test is done within the first minutes of life. It measures a baby’s breathing, heart rate, muscle tone, reflexes, and skin color.
A low score can mean the baby needed urgent help, such as oxygen or resuscitation. It can also be a sign that doctors were concerned about oxygen levels during delivery.
HIE and cerebral palsy
An HIE baby is at a higher risk of developing CP. This is because a lack of oxygen or blood flow can injure the parts of the brain that control movement and muscle tone.
Not every baby with hypoxic ischemic encephalopathy develops cerebral palsy. Some recover well. Others may have mild or severe movement problems that become clearer over time. The risk often depends on how long the brain went without oxygen and how serious the injury was.
When cerebral palsy is linked to HIE, spastic cerebral palsy is the most common type. This form causes stiff muscles and difficulty with movement.
2 types of spastic CP are seen more often in HIE babies:
- Spastic quadriplegia: Affects the arms and legs and is more likely after severe HIE
- Spastic diplegia: Mainly affects the legs and can happen after a moderate injury
Some children may also have mixed cerebral palsy, meaning they show features of more than one type.
In many cases, signs of cerebral palsy are not clear right away. Parents may first notice delays in rolling, sitting, crawling, or walking.
Doctors usually monitor babies with HIE closely so they can identify cerebral palsy or other developmental concerns as early as possible and start therapy and support.
What causes hypoxic ischemic encephalopathy?
Hypoxic ischemic encephalopathy happens when a baby’s brain does not get enough oxygen and blood flow. Some brain cells may recover, but others can be permanently injured.
“HIE is often seen in full-term infants and usually happens when the brain goes without enough oxygen during labor or delivery.”
The first injury occurs during the oxygen loss. A second wave of damage can happen when normal blood flow returns to the brain, according to HOPE for HIE.
Common hypoxic ischemic encephalopathy causes include:
- Abnormal fetal heart rate that signals distress
- Infection in the mother or baby
- Placental problems, such as abruption or poor blood flow
- Prolonged or obstructed labor
- Severe maternal bleeding
- Umbilical cord complications, including nuchal cord
- Uterine rupture
Not every difficult delivery results in hypoxic ischemic encephalopathy. However, when warning signs of oxygen loss are missed or not treated quickly, the risk of a hypoxic brain injury at birth increases.
HIE and medical negligence
Some cases of hypoxic ischemic encephalopathy happen even when doctors act quickly. Others occur when clear warning signs are missed or not taken seriously. Families depend on the delivery team to monitor oxygen levels and respond fast when something goes wrong.
Delays in a C-section or failure to act on fetal distress can lead to a hypoxic brain injury at birth. When oxygen loss lasts too long, brain cells can be permanently damaged.
“Conditions like cerebral palsy, hypoxic ischemic encephalopathy, and other forms of brain damage are often tied to mistakes during childbirth.”
— Ricky LeBlanc, birth injury lawyer at Sokolove Law
Parents are rarely told if mistakes were made. Families are often left with few answers after a difficult delivery. Getting clear information early can make a difference.
Cerebral Palsy Guide works with top birth injury attorneys who can help families in all 50 states.
Get a free case review now if you think your child’s HIE could have been prevented.
Hypoxic ischemic encephalopathy stages
Doctors use 3 stages to describe the extent of a baby's oxygen deprivation. These stages help determine the severity of HIE, guide treatment, and give families a sense of what to watch for.
However, they do not predict the future with certainty. Some babies improve quickly, while others need ongoing care and monitoring as they grow.
Stage 1 (mild HIE)
Mild HIE means birth injury symptoms are present but usually short-lived. A baby may be jittery, fussy, or harder to feed, but is often alert and breathing on their own.
Many babies with mild HIE recover in the first days of life, though doctors still watch development closely for any delays.
Stage 2 (moderate HIE)
Moderate HIE is more serious and often requires treatment in the NICU (neonatal intensive care unit). Babies may have low muscle tone, trouble feeding, or seizures. Many receive cooling treatment within the first hours after birth.
There is no single timeline for HIE stage 2 recovery, and doctors often take a wait-and-see approach. Some children improve with early therapy, while others develop symptoms of cerebral palsy or learning challenges over time.
Stage 3 (severe HIE)
Severe HIE involves significant brain injury and can affect breathing, movement, and organ function. Babies in this stage often need intensive life support and seizure management.
The risk of long-term disability or death is highest with severe hypoxic ischemic encephalopathy, and families usually need ongoing medical and developmental support as their child grows.
Talk to a nurse for free to get answers about your child’s HIE and learn what resources are available to help your family.
Kristin Proctor, RN
Registered Nurse for 20+ Years
How is HIE in newborns diagnosed?
Doctors diagnose hypoxic ischemic encephalopathy by looking at the baby’s condition after birth, what happened during labor and delivery, and results from imaging and lab tests.
Common tests and evaluations to diagnose HIE include:
- Physical exam: First step is to assess alertness, muscle tone, reflexes, breathing, and feeding
- Umbilical cord blood gas testing: Often done after delivery to check for acidosis linked to oxygen loss
- EEG monitoring: Used in the NICU to detect seizures and monitor brain activity
- Brain imaging (MRI): Magnetic resonance imaging is the most accurate way to identify brain injury from oxygen loss, often done after the baby is stable
- Head ultrasound: Early bedside scan in the NICU to look at the brain
- Organ function tests: Bloodwork to see if the heart, kidneys, or liver was affected
- CT scan: Less common in newborns, used in specific situations
No single test confirms HIE. Instead, the diagnosis is based on several findings that point to oxygen loss (birth asphyxia) and brain injury. These findings help confirm HIE and determine how severe the injury may be.
How do you treat hypoxic ischemic encephalopathy?
Treatment options for HIE depend on how severe the injury appears in the first hours of life. Some babies are closely monitored and may improve on their own. Other infants with hypoxic ischemic encephalopathy spend weeks or even months in the NICU.
Cooling therapy for hypoxic ischemic encephalopathy
The main treatment for moderate to severe HIE is therapeutic hypothermia, often called cooling therapy. This must begin within 6 hours of birth. A baby is placed on a cooling blanket or mattress, or fitted with a cooling cap, to lower body temperature for about 72 hours.
Cooling slows the injury process in the brain. It does not reverse damage that has already occurred, but it can reduce the extent of brain cell death. Babies receiving cooling are closely monitored with EEG (electroencephalogram), blood tests, and imaging during this time.
Other early treatments for HIE
Babies with hypoxic ischemic encephalopathy may also need:
- Anti-seizure medication
- Breathing support or a ventilator
- Blood pressure stabilization
- Heart and kidney monitoring
The goal is to stabilize the baby and limit further injury. Some children recover quickly, but other HIE babies need ongoing therapy, medical care, or continued support as they grow.
Long-term effects of HIE
Long-term effects of HIE are closely tied to how long a baby’s brain went without oxygen and blood flow. The longer the oxygen loss, the greater the risk of permanent injury.
In severe cases, damage can affect multiple areas of the brain at once, shaping how a child moves, learns, communicates, and processes the world.
“In some cases, it only takes a minute or a few minutes of oxygen deprivation to lead to an HIE diagnosis.”
— Kristin Proctor, RNC-OB, Cerebral Palsy Guide on-staff registered nurse
Some children with severe hypoxic ischemic encephalopathy go on to develop cerebral palsy or seizure disorders. Others may have ongoing feeding issues, vision or hearing problems, or delays that become clearer as they grow.
For many families, treatment and long-term care for HIE can be expensive, especially in more severe cases. If the injury was preventable, you may have options to pursue financial help for the lifelong care your child may need.
Get legal help for HIE
Severe HIE can lead to lifelong disabilities that affect how a child moves, learns, and communicates. Many families face years of therapy, medical appointments, and specialized care, which can create significant emotional and financial strain over time.
When hypoxic ischemic encephalopathy is tied to preventable errors made by health care professionals, families may have the right to pursue compensation to help cover future care and related costs.
An experienced birth injury attorney can review what happened and handle the legal process, so parents can focus on their child.
Our legal partners have recovered over $1 billion for families affected by birth injuries, including HIE.
Call (855) 220-1101 right now or fill out this form for a free case review to find out if we can connect you with a top birth injury law firm near you.
