HIE Causes

Quick Answer

HIE (hypoxic-ischemic encephalopathy) in newborns can be caused by issues during pregnancy, during labor and delivery, or after the baby is born. HIE happens when a baby’s brain doesn't receive enough oxygen or blood flow. Some cases of HIE are unavoidable, but others may stem from medical negligence. Learn more about HIE causes below.

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What Is Hypoxic-Ischemic Encephalopathy (HIE)?

Hypoxic-ischemic encephalopathy (HIE) is a brain injury that happens when there is a decrease in oxygen or blood flow to the brain.

A newborn with hypoxic ischemic encephalopathy (HIE) being treated in a cooling blanket.Sometimes called birth asphyxia, HIE can occur before, during, or after childbirth. Hypoxic-ischemic encephalopathy is considered a life-threatening birth injury. The longer the baby’s brain goes without oxygen or blood flow, the more severe the brain damage will be.

“Globally, HIE is estimated to cause more than 1 million deaths each year.”

—JAMA Pediatrics (American Medical Association Journal)

In mild cases of HIE, the baby will experience no long-term effects. However, babies diagnosed with moderate or severe HIE can be left with serious disabilities.

Types of Hypoxic-Ischemic Encephalopathy

The types of HIE are based on how severe the child’s condition is. These severity levels are largely classified by a scale called Sarnat staging, which categorizes HIE as mild, moderate, or severe.

Did you know

HIE is one of the most common causes of infant death and long-term disability. Moderate to severe HIE leaves 400,000 babies with neurodevelopmental impairment every year.

The Sarnat scale is used with electroencephalogram (EEG) findings to determine a child’s alertness, muscle tone, and the presence of seizures.

There are three types of hypoxic-ischemic encephalopathy in newborns:

  1. Mild HIE: Less than 5% of victims will develop a severe disability.
  2. Moderate HIE: Between 25-75% of cases result in a severe disability or early death.
  3. Severe HIE: Over 75% of babies will have a severe disability or die early from their complications.

What Causes HIE in Newborns?

Hypoxic-ischemic encephalopathy causes depend on when and how problems arise. HIE in newborns can stem from issues during fetal development, labor and delivery, or after childbirth.

Causes of HIE during pregnancy include:

  • Anemia (low red blood cell count) in the fetus
  • Fetal infection
  • Heart disease
  • Lung formation issues
  • Maternal diabetes
  • Maternal preeclampsia (high blood pressure)
  • Problems with blood flow to the placenta (the organ that delivers oxygen and nutrients from mother to baby)
  • Substance abuse

HIE causes during labor and delivery include:

  • Bleeding from the placenta due to placental abruption (tearing)
  • Low blood pressure in the mother
  • Problems with the umbilical cord
  • Rupture of the uterus

Hypoxic-ischemic encephalopathy causes after a baby is born (postnatal):

  • Low blood pressure
  • Major infections
  • Prematurity
  • Respiratory failure or cardiac arrest
  • Severe heart or lung disease
  • Trauma to the brain or skull

Many issues during the birthing process can increase the chances of hypoxic-ischemic encephalopathy. Some of these HIE causes are unavoidable. In other cases, medical malpractice could be at play, such as when a doctor or nurse fails to respond to fetal distress.

If you believe medical negligence caused your baby’s HIE, get a free legal case review today.

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Do you suspect your child’s birth injury was caused by medical malpractice?

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Symptoms of Hypoxic-Ischemic Encephalopathy

HIE symptoms depend on how severe the brain injury is and which parts of the baby’s brain were affected.

Babies with HIE may display symptoms like:

  • Abnormal movements or seizures
  • Decreased or increased reactions to sights and sounds
  • Developmental delays
  • Feeding problems due to muscle weakness in the mouth and throat
  • Floppy or weak muscle tone with poor reflexes
  • Movement abnormalities
  • Organ dysfunction, especially in the heart, lungs, kidneys, and liver
  • Pale or bluish skin
  • Weak cry
  • Weak or absent breathing patterns

Sometimes a baby who experienced HIE will not have symptoms, or medical professionals may downplay issues to cover up medical negligence. Therefore, it is extremely important to monitor your baby if you suspect there could be issues.

“The effects of HIE can become more noticeable as a baby develops. Sometimes, issues are not identified until school-age.”

—Massachusetts General Hospital

Our milestones quiz can help you determine if your child is experiencing developmental delays, which is one of the symptoms of HIE.

Getting a timely HIE diagnosis and prompt treatment will help ensure the best possible outcome for your baby.


Take Our Milestones Quiz

Taking note of your child’s physical, social, and emotional skills can help you determine if they potentially suffered from an injury at birth. An early diagnosis can help your child get the treatment they need as soon as possible.

Q1: How old is your child?

0-2 Months

3-4 Months

5-6 Months

7-9 Months

10-12 Months

13-18 Months

19-23 Months

24+ Months


  • Q2: Can your child hold their head steadily on their own?
  • Q3: Can your child push themselves up when they are lying on their stomach?
  • Q4: Has your child started to make smoother movements with their arms and legs?
  • Q5: Does your child smile at other people?
  • Q6: Can your child bring their hands to their mouth?
  • Q7: Does your child turn their head when they hear a noise?
  • Q8: Does your child coo or make gurgling noises?
  • Q9: Does your child follow things with their eyes?
  • Q10: Does your child try to look at their parents or caregivers?
  • Q11: Does your child show boredom, cry, or fuss when engaged in an activity that hasn’t changed in a while?
0-2-years old child


  • Q2: Can your child hold their head steadily on their own?
  • Q3: Does your child push down on their legs when their feet are on a flat surface?
  • Q4: Has your child started to roll over from their stomach to their back?
  • Q5: Can your child hold and shake a toy such as a rattle?
  • Q6: Does your child bring their hands to their mouth?
  • Q7: Does your child play with people and start to cry when the playing stops?
  • Q8: Does your child smile spontaneously, especially at people?
  • Q9: Does your child copy some movements and facial expressions of other people?
  • Q10: Does your child babble with expressions and copy sounds they hear?
  • Q11: Does your child cry in different ways to show hunger, pain, or tiredness?
  • Q12: Does your child respond to affection like hugging or kissing?
  • Q13: Does your child follow moving things with their eyes from side to side?
  • Q14: Does your child recognize familiar people at a distance?
3-4-years old child


  • Q2: Can your child roll over on both sides (front to back/back to front)?
  • Q3: Has your child begun to sit without support?
  • Q4: Does your child rock back and forth?
  • Q5: Can your child support their weight on their legs (and perhaps bounce) when standing?
  • Q6: Has your child begun to pass things from one hand to the other?
  • Q7: Does your child bring objects such as toys to their mouth?
  • Q8: Does your child know if someone is not familiar to them and is a stranger?
  • Q9: Does your child respond to other people’s emotions, such as a smile or a frown?
  • Q10: Does your child enjoy looking at themselves in the mirror?
  • Q11: Does your child look at things around them?
  • Q12: Does your child respond to sounds they hear by making sounds themselves?
  • Q13: Does your child make sounds to show joy or displeasure?
  • Q14: Does your child respond to their own name?
  • Q15: Has your child started to string vowels together, such as "ah," "eh," or "oh," or started to say consonant sounds such as "m" or "b"?
  • Q16: Has your child begun to laugh?
5-6-years old child


  • Q2: Can your child crawl?
  • Q3: Can your child stand while holding on to something to support them?
  • Q4: Can your child sit without support?
  • Q5: Can your child pull themselves up to stand?
  • Q6: Does your child play peekaboo?
  • Q7: Can your child move things from one hand to the other?
  • Q8: Can your child pick small things up, such as a piece of cereal, with their thumb and index finger?
  • Q9: Does your child look for things that they see you hide?
  • Q10: Does your child watch the path of something as it falls?
  • Q11: Does your child show fear when around strangers?
  • Q12: Does your child become clingy with adults who are familiar to them?
  • Q13: Does your child have favorite toys?
  • Q14: Does your child use their fingers to point?
  • Q15: Does your child understand “no”?
  • Q16: Does your child make a lot of repetitive sounds, such as “mamama” or “bababa”?
  • Q17: Does your child copy the sounds and gestures of other people?
7-9 years old child


  • Q2: Can your child stand alone with no support?
  • Q3: Does your child walk while holding on to furniture?
  • Q4: Can your child take a few steps without holding on to anything?
  • Q5: Can your child get into a sitting position without any help?
  • Q6: Does your child bang two things together when playing?
  • Q7: Does your child poke with their index finger?
  • Q8: Has your child started to use things like hairbrushes or drinking cups correctly?
  • Q9: Does your child find hidden objects easily?
  • Q10: Does your child play peekaboo or pat-a-cake?
  • Q11: Does your child become shy or nervous around strangers?
  • Q12: Does your child repeat actions or sounds to get attention?
  • Q13: Does your child put out an arm or leg to help when getting dressed?
  • Q14: Does your child cry when a parent leaves the room?
  • Q15: Does your child show that they have favorite things or people?
  • Q16: Does your child show fear?
  • Q17: Does your child say things such as “mama,” “dada,” or “uh-oh”?
  • Q18: Does your child try to say the words you say?
  • Q19: Has your child started to use gestures like waving or shaking their head “no”?
10-12 years old child


  • Q2: Can your child walk by themselves?
  • Q3: Does your child walk up stairs and run?
  • Q4: Does your child pull toys while walking?
  • Q5: Can your child drink from a cup on their own?
  • Q6: Can your child eat with a spoon on their own?
  • Q7: Can your child help undress themselves?
  • Q8: Does your child have occasional temper tantrums?
  • Q9: Does your child show affection to familiar people?
  • Q10: Does your child become clingy in new situations?
  • Q11: Does your child explore their environment alone with parents close by?
  • Q12: Can your child say several single words?
  • Q13: Can your child say and shake their head “no”?
  • Q14: Does your child point to show things to other people?
  • Q15: Does your child scribble?
  • Q16: Does your child know what ordinary products such as phones, spoons, and brushes are used for?
  • Q17: Can your child follow one-step commands such as “sit down” or “stand up”?
  • Q18: Does your child play with a doll or stuffed animal by pretending to feed it?
13-18 years old child


  • Q2: Has your child begun to run?
  • Q3: Has your child kicked a ball?
  • Q4: Can your child climb down and onto furniture on their own?
  • Q5: Can your child walk up and down stairs while holding on?
  • Q6: Can your child stand on their tiptoes?
  • Q7: Has your child thrown a ball overhand?
  • Q8: Does your child copy others, especially people older than them?
  • Q9: Does your child get excited around other children?
  • Q10: Has your child shown more independence as they've aged?
  • Q11: Does your child do what they were told not to do and become defiant?
  • Q12: Does your child point to things when they are named?
  • Q13: Does your child know names of familiar people or body parts?
  • Q14: Does your child say 2 to 4-word sentences?
  • Q15: Does your child repeat words they hear?
  • Q16: Does your child complete sentences and rhymes in familiar books?
  • Q17: Does your child name items in books, such as dogs, cats, and birds?
  • Q18: Does your child play simple pretend games?
  • Q19: Has your child started to use one hand more than the other?
  • Q20: Has your child begun to sort shapes and colors?
  • Q21: Does your child follow 2-step instructions, such as “pick up your hat and put it on your head?”
19-23 years old child


  • Q2: Can your child run easily?
  • Q3: Can your child climb?
  • Q4: Can your child walk up and down stairs with one foot on each step?
  • Q5: Can your child dress and undress themselves?
  • Q6: Does your child show affection for friends without being told?
  • Q7: Does your child take turns when playing games?
  • Q8: Does your child show concern when others are crying?
  • Q9: Does your child understand the idea of “mine" and "theirs"?
  • Q10: Does your child show many different emotions?
  • Q11: Does your child copy adults and friends?
  • Q12: Does your child separate easily from their parents?
  • Q13: Does your child get upset when there is a major change in their routine?
  • Q14: Does your child say words such as “I,” “me,” “we,” “you,” and some plural nouns?
  • Q15: Can your child say their first name, age, and gender?
  • Q16: Can your child carry on a conversation with 2 to 3 sentences?
  • Q17: Can your child work toys with buttons and other moving parts?
  • Q18: Does your child play pretend with dolls, animals, or people?
  • Q19: Can your child finish 3 or 4 piece puzzles?
  • Q20: Can your child copy a circle when drawing?
  • Q21: Can your child turn pages of a book one page at a time?
  • Q22: Can your child turn door handles?
24 months + old child

Long-Term Effects of Hypoxic-Ischemic Encephalopathy

Babies who have experienced HIE may make a full recovery. However, whenever the blood or oxygen supply to the brain is interrupted, there is a risk of long-term effects.

Long-term effects of HIE may include:

  • Autism
  • Behavioral challenges
  • Epilepsy
  • Hearing loss
  • Learning and attention disorders
  • Vision loss

Damage to bodily organs (such as the heart, liver, kidneys, and bowels) usually reverses, returning organs to normal.

Unfortunately, if the brain is injured, it may not make a full recovery, which can lead to permanent complications. Usually, the length of time the brain goes without oxygen determines the severity of brain damage.

At least 75% of babies with severe HIE will be left with a serious disability or even die early in life.

Severe cases of hypoxic-ischemic encephalopathy can cause serious lifelong conditions such as cerebral palsy.

HIE and Cerebral Palsy

When babies have experienced HIE, the immediate treatment involves cooling them (therapeutic hypothermia) for three days. This is done by placing the infant on a cooling blanket to reduce the chances of brain injury. However, this is not always effective.

“Despite medical advances and treatment with therapeutic hypothermia, over 50% of cooled infants are not protected and still develop lifelong neurodisabilities, including cerebral palsy.”

—National Institutes for Health (NIH)

If your baby is diagnosed with cerebral palsy, it is important to understand that it is a permanent condition that can cause severe physical and mental disabilities.

Cerebral palsy has no cure, and the prognosis can vary depending on how severe your baby’s condition is. Additionally, HIE CP epilepsy may occur, which can mean a lifetime of seizures and specialized care.

If you have questions about whether HIE could have caused your child’s cerebral palsy, talk with our registered nurses without delay. Getting the answers you need is critical in creating the best life plan for you and your child.

Nurse Beth Carter

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Call or chat with a caring, experienced nurse right now — we’re standing by to get you help and answers.

How Is HIE Diagnosed?

If HIE is suspected, a neurologist will monitor your baby for seizures and signs of brain dysfunction through an electroencephalogram (EEG).

An HIE diagnosis can also involve:

  • Checking for the presence of meconium (the baby’s first stool) in the amniotic fluid, which can be a sign of fetal distress
  • Conducting ultrasounds, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and other imaging tests to look for indications of a brain injury
  • Examining the baby’s Apgar scores (scores to measure an infant’s well-being)
  • Running blood tests to look for evidence of organ injury
  • Taking umbilical cord blood samples to look for acid build-up, another potential sign of fetal distress

Since the symptoms of HIE can vary, it is very important to monitor your baby for signs of a possible brain injury. This is especially true if there were any complications during your labor or delivery.

Treatment for HIE

Unfortunately, there isn’t any one specific HIE treatment, and the outcome for babies with HIE depends on the extent of their brain damage. Treatment options for hypoxic-ischemic encephalopathy are directed at which organs are affected.

“There is an enormous unmet clinical need for effective interventions against neonatal HIE.”

—Brain (Oxford Academic Journal)

The only brain-specific HIE treatment used to reduce the risk of long-term effects or disabilities is cooling therapy. Also called whole-body hypothermia treatment, cooling therapy involves reducing the baby’s body temperature to 92 degrees Fahrenheit for three days. During this time, the baby is given medications and monitored for any physical discomfort.

HIE treatment directed at other organs includes:

  • Anti-seizure medication if epilepsy is present
  • Assistance with kidney and liver function
  • Heart and blood pressure support
  • Ventilation for any breathing issues

After your baby is treated for HIE, the primary focus is helping them manage any remaining symptoms caused by their brain injury.

Hypoxic-Ischemic Encephalopathy Life Expectancy

A newborn's feet sticking out of a blanket.HIE life expectancy depends on how severe the condition is. Mild HIE does not usually affect a child’s life expectancy.

However, HIE baby life expectancy in moderate to severe cases may be affected, especially if the child develops co-occurring medical conditions that are linked with early death, such as cerebral palsy.

Families of babies with severe HIE often face lifelong treatments. Complications from HIE can create unforeseen issues for years, leaving caregivers with medical bills, missed work, and mental anguish.

If a medical mistake led to your baby’s HIE, you may be entitled to financial compensation. This money can help provide financial security and ensure your baby gets the best possible medical care for their condition.

Is HIE Caused by Malpractice?

Hypoxic-ischemic encephalopathy causes can occur before, during, or after childbirth. Therefore, it is possible that medical malpractice by health care providers can come into play at any time.

Examples of HIE causes related to medical malpractice include:

  • Failing to properly respond to fetal distress
  • Failing to provide cooling therapy to an HIE baby
  • Misreading fetal heart monitors
  • Neglecting to identify maternal risk factors, such as diabetes
  • Overusing delivery-inducing medications, such as oxytocin (Pitocin®)
  • Poor prenatal care, especially in a high-risk pregnancy

If you believe medical negligence was the cause of HIE in your baby, we may be able to connect you with an experienced birth injury law firm.

Get a free and confidential case review now to find out if you are eligible.

HIE Causes FAQs

Who is at risk for hypoxic-ischemic encephalopathy?

Newborns are at risk for HIE if certain problems occur during pregnancy, labor and delivery, or after the baby is born. Conditions such as preeclampsia, umbilical cord accidents, or severe prematurity can all put babies at risk for hypoxic-ischemic encephalopathy.

What are the symptoms of hypoxic-ischemic encephalopathy?

Symptoms depend on the causes of hypoxic-ischemic encephalopathy. Common signs that a baby has experienced HIE include a weak cry, floppy or weak muscles, poor reflexes, seizures, and pale/bluish skin.

Can you recover from hypoxic encephalopathy?

It depends on the severity. In mild cases, an HIE baby may be able to make a full recovery. However, in 75% or more of moderate or severe cases of HIE, serious disabilities or death occur.

How long do people with HIE live?

Babies who experience mild HIE can have little to no long-term disabilities. However, for those with severe HIE, lifelong conditions such as cerebral palsy, intellectual disabilities, and epilepsy can occur.

Sadly, early death may occur if the baby develops a serious co-occurring condition.

What is the medical cause of HIE?

The medical cause of HIE is a lack of oxygen or blood flow to the brain. Causes of hypoxic-ischemic encephalopathy can occur at any point from pregnancy until shortly after a baby is born.

Is HIE caused by malpractice?

Sometimes, yes. In some cases, HIE causes can be unpreventable. However, in other cases, hypoxic-ischemic encephalopathy causes involve medical negligence during pregnancy, labor, or delivery.

An example of HIE caused by medical malpractice is the failure to properly respond to signs of fetal distress, such as increased heart rate. A skilled birth injury lawyer may be able to help you determine whether a medical mistake caused your child’s HIE.

Birth Injury Support Team
Reviewed by:Beth Carter, RN

Registered Nurse, Legal Nurse Consultant Certified

  • Fact-Checked
  • Editor

Beth Carter has over 18 years of experience as a Registered Nurse. She spent nearly half of that time working in labor and delivery units. This, combined with her own experience giving birth to a premature baby, ignite Beth’s passion for helping new mothers access the information and resources they deserve.

The Birth Injury Justice Center was founded in 2003 by a team of legal professionals to educate and empower victims and families affected by birth injuries. Our team is devoted to providing you with the best resources and legal information for all types of birth injuries.

View Sources
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  2. Finder, M. (2020, January 1). Two-year neurodevelopmental outcomes after mild hypoxic ischemic encephalopathy. JAMA Pediatrics. Retrieved February 3, 2023, from https://jamanetwork.com/journals/jamapediatrics/fullarticle/2754822
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  8. Rocha-Ferreira E, Poupon L, Zelco A, Leverin AL, et al. (2018, October 1). Nair S, Jonsdotter A, Carlsson Y, Thornton C, Hagberg H, Rahim AA. Neuroprotective exendin-4 enhances hypothermia therapy in a model of hypoxic-ischaemic encephalopathy. Brain 141(10), 2925-2942. Retrieved February 2, 2023, from https://doi.org/10.1093/brain/awy220
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Nurse Beth Carter

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