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Birth Injury

What is HIE (Hypoxic Ischemic Encephalopathy)?

Hypoxic Ischemic Encephalopathy

It can be overwhelming trying to decipher medical jargon, especially when a lot of terms are being thrown at you so quickly. Unless you are medical professional who has spent years learning about birth injuries, the term HIE (or Hypoxic Ischemic Encephalopathy) probably means nothing to you. Let’s break it down:

  • Hypoxic means a lack of oxygen.
  • Ischemic means restricting bloodflow.
  • Encephalopathy means affecting the brain.

When you put it all together, HIE most commonly means that brain cells have been hurt because the brain didn’t get enough oxygen delivered through blood flow into the brain. Usually, this means that there were low levels of oxygen in the blood or not enough flow of oxygen to the brain.

When Does HIE happen?

A child can suffer HIE prior to birth, during birth, after birth, and even during childhood. Similar diagnoses include perinatal encephalopathy, perinatal asphyxia, neonatal encephalopathy, or birth asphyxia.

What Causes HIE?

Unfortunately, there are many potential causes for HIE. Some ways it occurs are: placental insufficiency, uterine rupture, placental abruption, true umbilical knots, cord compression, maternal blood clotting disorders, fetal maternal hemorrhage, extremely low maternal blood pressure, trauma during delivery, placental blood clots, shoulder dystocia, cord prolapse, aneurysm rupture, cardiac arrest and near SIDS events.

How is HIE Diagnosed?

One way to diagnose HIE in a newborn baby is using the Sarnat Scale, which is based on how the appears after birth or injury, and includes imaging such as an EEG, ultrasound and MRI, and checking cord blood gas levels.


Common symptoms to look for are:

  • Low or absent heart rate
  • Slow, irregular, depressed, or absent breathing
  • Acidosis
  • Seizures
  • Stained meconium
  • Low muscle tone or “floppy”
  • Skin color is blue or very pale
  • Absent or depressed reflexes
  • Apgar score of less than three, lasting longer than five minutes

What Can You Do if Your Baby Has HIE?

One possible treatment for HIE is to place the baby into therapeutic hypothermia (or cooling). This treatment can be performed on the whole baby’s body, or by a cooling cap on the head. Cooling is known to reduce the chances of death and disability in many cases where a baby has been diagnosed with HIE.

Therapeutic Hypothermia Baby Cooling