How Is Hypoxic-Ischemic Encephalopathy (HIE) Diagnosed?

Hypoxic-ischemic encephalopathy (HIE) is generally diagnosed by a physician once signs of oxygen deprivation (birth asphyxia) become evident. The diagnosis is typically based on a combination of medical history, physical and neurological exams, laboratory results, and neuroimaging. Many of these tests and studies assess brain injury severity and evaluate the status of the baby’s organ systems. Babies with neonatal seizures are usually evaluated for HIE.

Diagnosing HIE: signs, symptoms, and tests

Signs and symptoms of hypoxic-ischemic encephalopathy (HIE) may include the following (1):

  • Low APGAR Scores: An APGAR score of less than 5 at 5 minutes and 10 minutes may indicate encephalopathy. 
  • Profound metabolic or mixed acidemia in an umbilical artery blood sample (the baby’s blood is acidic/has a low pH).
  • Acute brain injury seen on an MRI or MRS that shows hypoxic-ischemia
  • Multiple organ problems (e.g., the involvement of the lungs, liver, heart, and intestines)
  • Fetal heart rate patterns consistent with a peripartum or intrapartum event

Tests and studies are conducted once medical professionals have observed signs and symptoms of HIE. These include (1):

  • MRI scan: This test uses magnetic waves to make pictures of structures inside the baby’s brain. This can show the pathogenesis and prognosis of encephalopathy. 
  • Cord blood samples: Cord blood can show the umbilical arterial and venous pH.
  • A complete blood count: This can determine hemorrhage, thrombocytopenia (low platelet count), or infection.
  • Arterial blood gases: These tests are used to help determine how well the baby is breathing, the pH of the blood (acidic, basic, or normal), and if any acidemia present is due to breathing or kidney problems.
  • Bacterial blood cultures: To rule out sepsis and viral cultures if necessary.
  • Lumbar puncture: If there is a concern that it might be an intracranial infection.
  • EEG (electroencephalogram): This test records the activity of the baby’s brain by measuring electrical currents through the brain. This can distinguish seizures from other issues and determine their cause.
  • Ultrasound: This test uses sound waves to evaluate echos in the brain suggestive of cerebral edema and ischemia. This can suggest the timing and extent of HIE. It can locate hemorrhages and determine ventricular size with acute sensitivity. 

The importance of early diagnosis

Michigan hypoxic ischemic encephalopathy (HIE) lawyers discuss brain cooling treatment for HIE

  • If physicians promptly diagnose HIE in a newborn, there may still be time to prevent or limit permanent damage. There is a groundbreaking treatment for HIE called hypothermia therapy, also known as brain cooling, body cooling, and therapeutic hypothermia (1). Research shows that when hypothermia therapy is performed within six hours of the time the baby was deprived of oxygen, it can reduce the chance of death, as well as the extent and occurrence of permanent disability (2). If doctors fail to quickly recognize the signs of HIE and do not administer cooling in time, the infant’s chances of developing serious, lifelong conditions is much higher. These conditions include:

Video:  Michigan birth injury lawyers discuss hypoxic-ischemic encephalopathy (HIE)

In this video, Michigan birth injury lawyers Jesse Reiter and Rebecca Walsh discuss the causes of and treatments for HIE.

Award-Winning Michigan Hypoxic-Ischemic Encephalopathy (HIE) LawyersABC Law Centers Birth Injury Attorneys

Sometimes a child will have signs and symptoms of HIE immediately after birth – especially if it was a complicated birth or if errors occurred in the delivery room. Other times, HIE may not be identified until years after a hypoxic event. If your child was diagnosed with HIE, you should contact a law firm that focuses on this area. The Michigan HIE lawyers at ABC Law Centers (Reiter & Walsh, P.C.) have been helping children affected by HIE nationwide for decades, and are very skilled at handling the complex issues involved with birth injury cases.

 More information on HIE


  1. Wu, Y. (2019, July 10). Clinical features, diagnosis, and treatment of neonatal encephalopathy. Retrieved from
  2. Mosalli R. (2012). Whole body cooling for infants with hypoxic-ischemic encephalopathy. Journal of clinical neonatology, 1(2), 101-6.