Hypoxic Ischemic Encephalopathy (HIE) and Cerebral Palsy

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Hypoxic-ischemic encephalopathy (HIE) is a type of oxygen deprivation that occurs during labor and delivery. HIE can lead to brain damage and, in some babies, to a disability like cerebral palsy. The degree of disability varies by individual and is highly dependent on how long the baby lacked oxygen.

What Is Hypoxic Ischemic Encephalopathy?

HIE is oxygen deprivation-caused brain damage that occurs during the perinatal period, in the weeks leading up to birth, or during labor and delivery.

It is most common in full-term infants but may also happen in premature infants.[1] The resulting brain damage may cause a variety of disabilities that depend on the area of the brain that was affected and the severity of the oxygen deprivation and resulting brain damage.

What Causes HIE?

The direct underlying cause of HIE is asphyxia. When oxygen is deprived, there will be some degree of resulting brain damage.

What causes asphyxia is more complicated and may not be determined for every infant. Several possible causes include:

• Medical negligence
• Heart complications
• Placental abruption
• A prolapsed umbilical cord
• Labor and delivery stress
• Maternal low blood pressure
• Maternal blood that is low in oxygen
• Umbilical cord complications
• An intrapartum hemorrhage
• Prolonged labor
• Trauma to the brain or skull
• Congenital brain defects
• Maternal diabetes
• Malformed lungs
• Preeclampsia, or high blood pressure
• An abnormal position of the fetus
• Interrupted breathing
• Uterine or vasa previa rupture

What Are the Symptoms of HIE?

The mildest cases of HIE may go with symptoms undetected and often resolve within 24 hours. Mild HIE may be characterized by poor feeding, excessive crying, irritability, or slightly increased muscle tone in the infant.

More moderate HIE may cause lethargy, significantly low muscle tone, slow or absent reflexes, and even seizures. Infants with moderate HIE can recover or may end up with only mild disabilities.[2]

Severe HIE usually leads to more severe permanent disabilities. Seizures may occur with HIE and may be resistant to routine treatment. Other symptoms of severe HIE include:

• Dilated pupils
• No reaction to stimuli
• Irregular breathing
• Absent infant reflexes
• Irregular heart rate
• Irregular blood pressure
• Stupor
• Coma

How Do Doctors Diagnose HIE?

Doctors can perform tests to confirm the brain damage if they see signs and symptoms. They can determine where the injury occurred and the severity. Tests for HIE include: 

• Doctors use imaging tests like MRIs that look for areas of damage in the brain.
• Doctors also look at the pH of a sample of umbilical cord artery blood. If it is less than seven, this supports a diagnosis of HIE.
• They will also consider the infant’s Apgar score. This is a routine evaluation that is done at 1 and 5 minutes after a baby is born to evaluate the baby’s heart rate, reflexes, skin color, muscle tone, and breathing. The healthier the baby, the higher the score is. Apgar scores range from 0 to 10. An Apgar score of three or less is also used as supporting evidence for HIE.

How Is HIE Treated?

Recognizing the signs of HIE and getting a diagnosis as soon after birth as possible is crucial. Treatments can help, but they need to be administered as soon as possible. These include:[3]

• Making sure the infant has adequate ventilation
• Using a respirator to support breathing
• Maintaining blood pressure
• Managing fluids
• Managing blood sugar
• Treating seizures

It is also important to avoid overheating the infant because this can worsen the condition and cause worse long-term outcomes.

While overheating can cause more harm, researchers have actually developed a treatment that uses cold temperatures to treat infants with HIE. Hypothermia, or “cooling therapy,” can be used to drop the baby’s temperature and limit the amount of lasting damage to the brain.

Studies have shown that babies that have suffered moderate to severe HIE and that undergo this hypothermia treatment have better outcomes.

It is thought that the cold temperature slows the death of brain cells and prevents the formation of toxic substances in the brain that cause damage. For this treatment, the infant is cooled to about 33 degrees Celsius (91 degrees Fahrenheit) for the first 72 hours.

Can HIE Be Prevented?

Hypothermia treatment has been proven to be an effective way to limit the lasting damage and long-term disabilities that babies born with HIE experience. However, there is no cure for HIE, and any baby may face disability because of it, regardless of treatment.

Doctors and parents can work together to ensure safe labor and delivery. Regular checkups for the mother to maintain her health, monitoring the fetus during labor and delivery, and having trained and experienced health care practitioners on hand all help to prevent the kinds of complications that can lead to HIE.

HIE can lead to serious consequences for a baby and the family. Severe brain damage can lead to lifelong disabilities that limit a child’s quality of life and may cause stress, financial problems, and other issues for a family.

If your child suffered from HIE during labor and delivery, you need to know your rights. Advocate for your child to be diagnosed and treated as quickly as possible and to find out if someone’s negligence contributed to your child’s brain damage.

Consult with a birth injury lawyer or legal team that can help you understand what you and your child’s rights are, how you can seek justice or compensation, and what steps you need to take next to best provide for your child.