Hypoxic-ischemic encephalopathy, or HIE, is a medical term for an injury caused by lack of oxygen to a baby's brain. Humans need to breathe. No matter what age you are, blood MUST circulate to deliver oxygen and nutrients to your cells and remove waste and toxic buildup. Without oxygen, your cells will die. If enough cells are affected, serious medical conditions or death occur. During pregnancy, labor, and delivery, babies are especially vulnerable to lack of oxygen. During the vital perinatal period - a few weeks before, during, and after birth - any interruption of oxygen to the developing brain is dangerous. Blood circulation is what supplies the body’s cells with oxygen for proper function. When the brain is deprived of oxygen, severe brain damage or death can occur.

Hypoxic-Ischemic Encephalopathy, or HIE, explained:

Out of the body’s entire oxygen supply, 20% of oxygen is consumed by the brain. ¹ Babies receive oxygen and nutrients, and also get rid of waste through the umbilical cord. Instead of breathing, oxygen is delivered to the baby from the mother in the umbilical cord.

Without a steady flow of blood delivering oxygen, the baby can be quickly be injured. During the birthing process, it is especially important that the baby gets oxygen. Cells need oxygen to survive. If the baby doesn’t receive enough oxygen, the baby’s cells begin to die.

If too many brain cells die, a brain injury occurs, and the baby may have permanent brain damage. Hypoxic-ischemic encephalopathy (HIE) is a medical term that refers to the damage caused by lack of oxygen.

HIE is a leading cause of cerebral palsy. HIE can also cause many other serious birth injuries, including: autism, mental retardation, and visual motor or visual perceptive dysfunction. Additionally, HIE can cause increased hyperactivity and attention disorders, and epilepsy.

What Causes HIE?

Hypoxic-ischemic encephalopathy is a diagnosis that means the baby’s brain was injured by a lack of oxygen. “Hypoxia” means there isn’t enough oxygen in the blood. “Ischemia” means that not enough blood is flowing to the baby. “Encephalopathy” refers to the brain damage that is caused by the lack of oxygen flow to the brain.

Here are some of the potential causes of HIE:

  • Birth trauma or full-term injuries
  • C-section errors or delays
  • CPD
  • Fetal monitoring errors or neglect
  • Fetal stroke
  • Infections
  • Macrosomia
  • Fetal distress
  • Birth asphyxia
  • Brain bleeds
  • Placenta complications
  • Umbilical cord issues
  • VBAC

There are two injuries that are caused by HIE:

Brain cells need oxygen to make energy. Oxygen deprivation causes cells to starve and die.
Oxygen deprived cells produce lactic acid and toxins. The lactic acid and toxins then re-circulate throughout the body through the blood stream, causing additional harm.

HIE Statistics

About 1-3 babies in 1,000 suffer an HIE injury at or near the time of birth.² Approximately 15-20% of these babies with birth trauma will die after being born, and another 25% will have permanent injuries.³

Cerebral palsy, seizures, mental retardation, eye sight problems, personality disorders, autism, and epilepsy are all injuries caused by HIE. Other organs may be damaged, too, such as the heart, liver, kidneys, and the central nervous system.

Severe cases of HIE may be identifiable immediately after delivery. However, sometimes HIE can go undetected until later, as the child grows older.

Medical Mistakes Can Cause HIE

Is HIE Preventable?

Yes, some cases of HIE can be prevented. HIE can be caused by a lack of oxygen, untreated jaundice, infection, physical trauma, or low glucose levels.

Lack of oxygen can be caused by: contractions, problems with the umbilical cord, uterine rupture or placental abruption, and other conditions.

The medical term for when a baby doesn’t get enough oxygen is “asphyxia.” There are two types of asphyxia. “Near total asphyxia” or “acute profound asphyxia,” which happens when the baby is getting almost no blood flow or oxygen.

When a baby gets less oxygen than it needs for a longer period of time, that is called “partial prolonged asphyxia.” Another term for the condition is “partial prolonged hypoxia.”

When a baby doesn’t get enough oxygen, the baby can develop “metabolic acidosis.” Metabolic acidosis is a dangerous chemical imbalance that occurs when the baby doesn’t have enough oxygen.

Brain cells need oxygen for the chemical reaction that creates energy for the cell. If the brain cells don’t have enough oxygen, they produce lactic acid. Lactic acid damages the cells.

When metabolic acidosis occurs, lactic acid builds up and destroys brain cells, causing brain damage. This brain damage caused by metabolic acidosis can lead to HIE, cerebral palsy, and other brain impairments.

Metabolic acidosis is detected by testing the baby’s blood. A sample is taken either from the umbilical cord or from the baby. The test then checks the pH and base of the baby’s blood for irregularities.

Here are lists of some of the known causes of HIE:

Maternal Causes

  • Hypotension (low blood pressure)
  • Hypertension (high blood pressure)
  • Infections
  • Vascular or blood disorders
  • Thyroid disorders

Placenta & Umbilical Cord Causes

  • Umbilical cord prolapse
  • Nuchal cord (cord around the baby’s neck)
  • Umbilical cord knot
  • Umbilical cord abnormality
  • Uterine rupture
  • Uterine hyperstimulation or tachysystole
  • Placental abruption
  • Placenta previa
  • Placental insufficiency
  • Preeclampsia

Fetal Causes

  • Fetal intolerance to labor
  • Blocked airways
  • Anemia
  • Infection
  • Cardiomyopathy
  • Severe circulatory insufficiency
  • Severe respiratory distress syndrome (RDS)
  • Shock

Delivery problems

  • Delay in performing Cesarean section
  • Physical trauma during labor and delivery including the use of forceps or a vacuum extractor
  • Getting stuck in the birth canal
  • Excessive pulling
  • Breech extraction
  • Dropped glucose levels
  • Untreated jaundice

Many of the Causes of HIE Are Preventable with Careful Monitoring and Quick Treatment.

Is HIE a Serious Condition?

Birth Asphyxia Causes 23% of Neonatal Deaths Globally.⁴

Children with hypoxic-ischemic encephalopathy can experience serious brain damage and possible disabilities. The extent of brain damage depends on a number of factors:

  • How severe the oxygen deprivation was
  • The amount of time that the baby was deprived of oxygen
  • The health and condition of the baby before the oxygen deprivation occurred
  • How the baby’s health was managed after the oxygen deprivation occurred

HIE injuries occur when the fetus or baby’s brain is deprived of oxygen. During the labor and delivery process, it is critical that the baby receives a steady supply of oxygen. If the baby is deprived of oxygen for too long, serious injuries may occur. 

If your child was born with HIE, it may be due to a preventable medical error. Some errors that can result in HIE include:

  • If your child was not timely delivered via C-section 
  • If your child was not given hypothermia treatment

If you have questions about your child’s HIE diagnosis, we may be able to help you find answers.


Contact an HIE and Birth Injury Attorney

If your child was hurt by HIE, you probably have a lot of questions. We can help you find answers. We can help you understand your legal rights if a medical professional made a medical error treating you or your baby.

We can help determine whether you are legally entitled to recover damages for negligent medical care.  Legal compensation can help pay for medical bills, rehabilitation, therapy, expenses, lost earnings, and physical pain and suffering.

It can be very expensive to afford the proper treatment for a child injured by HIE. If your child was severely injured, your child may require constant care and supervision. Don’t wait to act, the statute of limitations may bar your ability to bring a case if you wait too long.

We will fight to protect your child’s rights and ensure that you are fairly and fully compensated for your losses. Call +1 (844) 232-9228 or email us a [email protected].

Free Case Evaluation

If you would like to know if your child’s HIE was preventable, please contact birth injury attorney Laura Brown. Consultations are free – and there is no obligation. Call +1 (844) 232-9228 or email us a [email protected].


1. Li, Yong et al. “Fetal stress and programming of hypoxic/ischemic-sensitive phenotype in the neonatal brain: mechanisms and possible interventions.” Progress in neurobiology vol. 98,2 (2012): 145-65. doi:10.1016/j.pneurobio.2012.05.010
2. Kurinczuk, J. J., White-Koning, M., & Badawi, N. (2010). Epidemiology of neonatal encephalopathy and hypoxic–ischaemic encephalopathy. Early human development, 86(6), 329-338.
3. Zanelli, S. A., Stanley, D. P., & Kaufman, D. A. (n.d.). What is the global prevalence of hypoxic-ischemic encephalopathy (HIE)? September 16, 2019, from https://www.medscape.com/answers/973501-106461/what-is-the-global-prevalence-of-hypoxic-ischemic-encephalopathy-hie
4.“Hypoxic-Ischemic Encephalopathy.” Medscape.com, 19 Oct. 2019, emedicine.medscape.com/article/973501-overview.