What is Hypoxic Ischemic Encephalopathy

Hypoxic ischemic encephalopathy, or HIE, is a severe birth complication that affects preterm and full-term infants. HIE is a brain injury caused by oxygen deprivation during fetal development, labor, delivery, or during the postnatal period. Damage caused by HIE can be significant and devastating. Forty to sixty percent of infants affected by HIE either die by age 2 or have severe disabilities. Twenty-five percent of surviving infants will develop severe and permanent neuropsychological consequences, including mental retardation, visual motor or perceptive visual dysfunction, increased hyperactivity, cerebral palsy, and epilepsy. It’s important to understand and recognize potential causes of HIE in advance, as up to 30 percent of HIE cases are preventable.

During fetal development, HIE can be caused by preeclampsia, maternal diabetes, and vascular disease. A uterine rupture, which can occur spontaneously or due to a traumatic incident, may lead to HIE. Problems with the placenta, such as detachment of the placenta from the inner wall of the uterus or instances where the placenta covers the opening of the cervix, may also lead to HIE. In addition, fetal infections, fetal anemia, and fetal lung malformation, as well as a mother’s drug or alcohol use during pregnancy, can cause HIE.

Several factors during labor and delivery can lead to HIE. Umbilical cord prolapse and compression is one cause, with umbilical cord compression occurring in approximately 1 in 10 deliveries. Failure to properly monitor a baby’s heartbeat during labor can result in HIE. Because babies born prematurely are more likely to have underdeveloped lungs and immune systems, preterm babies are at a greater risk of experiencing HIE. A breech presentation or a delayed delivery, such as when a baby gets stuck in the birth canal or a baby is too large for a vaginal delivery and doctors fail to perform a timely C-section, can result in HIE.

During the postnatal period, infants can develop HIE because of postpartum complications. Lung or heart disease or severe infection may cause HIE. Brain or skull trauma or a near-miss event of sudden infant death syndrome, known as SIDS, can inhibit oxygen and blood flow and cause HIE. A baby’s extremely low blood pressure or respiratory failure also can be a factor. Babies can develop HIE because of hypoglycemia or hyperglycemia, leading to a hard sugar crash, which can cause seizures and a lack of oxygen. Children who experience cardiac arrest can experience HIE.

HIE has three stages, and its symptoms depend upon the stage and the areas of the brain affected. The first stage is mild hypoxic ischemic encephalopathy, which will typically resolve itself within a few days without any long-lasting effects. In mild HIE, the baby is stiff, seems hyper alert, and may be floppy and unreactive to sights or sounds. The baby may also exhibit behavioral abnormalities such as irritability, poor feeding, or excessive crying or sleepiness. The second stage is moderate HIE, where the infant is lethargic and may have sluggish or non-existent sucking and grasping reflexes and may experience apnea and seizures within 24 hours after birth. However, these symptoms often resolve themselves within a few weeks.

The third stage is severe HIE. The infant may fail to respond to physical stimuli and experience decreased muscle tone. Breathing may be irregular, and the infant may lack sucking, swallowing, or grasping reflexes and demonstrate eye motion disturbances and dilated pupils. Infants may experience delayed and severe seizures that resist conventional treatments, as well as heart rate and blood pressure irregularities. Stupor and coma can occur, as well as cardiorespiratory failure, which is often fatal.

The seriousness of a baby’s condition and the lifelong complications depend upon several factors: the length of time the baby was without oxygen, the baby’s birth weight, overall health, and the speed and efficiency of treatment. Diagnosing HIE early is vital because timely treatment can reduce the severity. Short-term treatment can include therapeutic hypothermia for 72 hours, a ventilator, and medications to treat seizures, heart rate, and blood pressure.

Parents of children with brain injuries can enhance their child’s quality of life by consulting with a medical team and following their doctor’s advice. Remain open to treatment options and take an active role in physical and occupational therapy settings. Help your children set realistic and achievable goals and celebrate their accomplishments with them.

Since up to 30 percent of hypoxic ischemic encephalopathy cases are preventable, understanding the causes and risks of HIE is critical. Be sure to consult with your physicians to reduce the risk of medical negligence that can lead to HIE. A birth injury is devastating, but the proper guidance and tools can restore hope for the future. Many children with special needs thrive with a routine, and parents can be instrumental in establishing that routine. It’s important that parents pay attention to their own wellness too, seeking support and counseling if needed. Keep in mind that you’re not alone. You can find abundant resources to help you learn more about causes of HIE, treatments, family forums, parent support groups, and more at BirthInjuryCenter.org.