The Importance of Early Detection
Medical professionals should evaluate babies for hypoxic-ischemic encephalopathy (HIE) if there are labor and delivery complications or signs of fetal distress during the birthing process, as well as if newborns exhibit certain early signs of brain injury. Prompt assessment is critical because if detected very quickly, HIE can be treated with hypothermia therapy. This can prevent or minimize permanent damage, but it must be administered within hours of birth in order to be effective.
Babies who experienced oxygen-depriving conditions in utero, during the birthing process, or shortly after birth should always be tested for HIE. Sometimes, a newborn may appear healthy even if they have sustained a birth injury. However, in many cases, babies will exhibit some of the following signs and symptoms of HIE:
- Breathing problems
- Seizures (click here for more information about recognizing seizures in infants)
- Trouble feeding (difficulty latching on, sucking, or swallowing)
- Low muscle tone (the baby is floppy or limp)
- Abnormal consciousness or coma
- Abnormal responses to light
Tests and evaluations used to diagnose HIE include the following:
The APGAR score: This is a tool used to assess a newborn’s overall health. Low APGAR scores can be indicative of HIE and other health concerns. APGAR is an acronym that stands for:
- Appearance: For example, does the baby’s skin tone look blue or pale?
- Pulse: Does the baby have a normal heart rate?
- Grimace (reflex irritability): How does the baby respond to stimulation?
- Activity: Does the baby have joint movement, the ability to flex, etc?
- Respiratory effort: Is the baby breathing/crying?
Brain imaging: Brain imaging involves technologies such as MRIs, CT scans, and ultrasound, which can be used to take pictures of a baby’s brain and identify whether there is an injury due to oxygen deprivation. MRIs are the preferred method of infant brain scanning to diagnose HIE.
Umbilical cord blood gas tests: Immediately after birth, especially if there were complications or the mother had a high-risk pregnancy, physicians should collect a sample of the umbilical cord blood. This can help determine whether a baby experienced fetal distress (that is, was deprived of oxygen for a period of time). Babies with HIE may have an unusually low pH in their cord blood.
EEGs: Because seizures are a very common sign of HIE, electroencephalogram (EEG) can be used to detect abnormal activity in the brain. The presence of seizures is not a sure indication that a baby has HIE, but the two conditions often co-occur. Neonatal seizures should also be promptly treated, because they can worsen existing brain damage.
As previously discussed, early recognition of HIE is extremely important because it provides the opportunity for a baby to get hypothermia therapy. However, in many cases, HIE is not detected until months or years after birth, when the baby begins to miss developmental milestones such as playing, smiling, crawling, or talking.