What Are the Effects of Brain Hypoxia in Newborns?

Associated Conditions, Birth Injury, Causes of Cerebral Palsy

Hypoxia is what happens when a baby suffers insufficient oxygen before or during birth. The insufficiency can be due to lack of adequate oxygen in the blood delivered to the baby through the umbilical cord or due to interruption of the blood flow, either intermittently or totally. This type of brain damage from hypoxia is often called hypoxic ischemic encephalopathy (HIE), and it can have serious, life-long consequences, including cerebral palsy.

What Causes Hypoxic Ischemic Encephalopathy?

HIE is a brain injury that can happen when a baby’s brain does not receive enough oxygen or blood flow for a period of time. Any interruption of blood flow and oxygen to a fetus or newborn baby can have potentially life-threatening consequences. When blood flow is completely cut off permanent damage can occur in minutes. If the blood flow is intermittently interrupted, damage may take hours, since the baby can sometimes recover during periods of adequate flow. Eventually, however, the baby’s reserves are depleted, and damage will occur.

This lack of blood flow or oxygen can happen during the mother’s pregnancy, during labor and delivery, or even after birth during the newborn stage. It can be triggered by:

  • Problems with blood flow to the placenta
  • Preeclampsia or maternal diabetes
  • Maternal vascular disease
  • Maternal or fetal infections
  • Umbilical cord injuries or complications
  • Umbilical cord compression
  • Abruption of the placenta or rupture of the uterus
  • Excessive maternal bleeding
  • Fetal breech position without proper intervention
  • Prolonged late stages of labor
  • Untreated low blood pressure in the mother
  • Brain trauma to the baby during delivery
  • Preterm birth, labor induction, or delayed C-section
  • Forced extraction of the baby by forceps or vacuum
  • Lack of fetal or maternal monitoring
  • Excessive administration of labor stimulating drugs

In some cases, it is not known immediately when the fetus or newborn baby begins experiencing a lack of oxygen, but every second counts. When your baby’s brain and body do not get enough oxygen and nutrients, they cannot work properly, and brain damage from hypoxia can result after even just a few moments.

What Are the Symptoms of Brain Hypoxia?

Symptoms of brain hypoxia can be present immediately, even in subtle ways. For this and other reasons all babies should be assessed for developmental and health concerns at birth. When birth complications or other neonatal risk factors are present, HIE may be suspected even before symptoms present. A medical assessment—Sarnat staging—is determined by the symptoms of HIE as well as the areas of the brain that were affected, some of which are evident during the mother’s labor and some of which can be seen immediately after birth, including:

  • Abnormal fetal heart rate
  • Poor umbilical cord gasses
  • Low Apgar scores
  • Presence of meconium-stained fluid
  • Respiratory support needed within the first several minutes
  • Damage to organs other than the brain, such as liver or kidneys

Your healthcare provider may also assess or review your child’s:

  • Mental status
  • Suck reflex
  • Startle reflex
  • Autonomic function
  • Pupils
  • Seizures
  • EEG for brain wave activity

When HIE is suspected, a neurologist should assess your baby and rule out other causes of symptoms.

How is HIE Diagnosed and Treated?

When birth complications or other neonatal risk factors are present, babies may be assessed for HIE even before significant symptoms present in order to initiate treatment as soon as possible. Many parents are familiar with the term APGAR score, even if they do not know exactly what it means.

Newborns are all assessed using this scale, which stands for “Appearance, Pulse, Grimace, Activity, and Respiration.” This is a general assessment of a newborn’s heart rate, muscle tone, and other biological functions that are used to determine if the baby might need immediate treatment or urgent further assessment. Apgar tests are performed at one minute after birth and again at five minutes. Sometimes, a low Apgar score is evidence that hypoxia occurred.

The Apgar test has saved numerous babies’ lives since its introduction, but medical professionals need to be especially thorough in their assessments of babies’ gestational, physical, and neuromuscular maturity when it comes to identifying signs of brain hypoxia in newborns. Evaluations of a baby’s neuromuscular system look at six different areas, and a score is assigned to each area:

  1. Posture. How does the baby hold its arms and legs?
  2. Square window. How far can the baby’s hands be flexed toward the wrist?
  3. Arm recoil. How much do the baby’s arms “spring back” to a flexed position?
  4. Popliteal angle. How far do the baby’s knees extend?
  5. Scarf sign. How far can the baby’s elbows be moved across the chest?
  6. Heel to ear. How close can the baby’s feet be moved to the ears?

In addition to the Apgar test, laboratory assessments, and physical assessments, radiological and neuroimaging methods, such as ultrasounds and MRIs, also can be used to diagnose suspected cases of HIE. There is no cure for HIE, and there is not even one definitive treatment. Instead, various treatments should be used to alleviate the symptoms of brain hypoxia, especially in the baby’s organs:

  • Supporting the heart and blood pressure
  • Sustaining kidney and liver function
  • Ventilating mechanically or other breathing support
  • Treating seizures with medication
  • Cooling treatments to minimize progression

How Does Hypoxia Affect the Brain?

Brain cell death occurs within minutes of oxygen deprivation. If your baby is diagnosed with HIE, your baby will be assessed for their Sarnat score, a widely used tool that helps to classify the severity of a hypoxic-ischemic brain injury. HIE is classified into three stages, which can help you to better understand the effects of hypoxia on the brain.

Stage I HIE

Stage I HIE is considered mild but may still have significant effects on your baby. Your baby might experience a few worrisome symptoms, but they should last less than 24 hours after birth, and long-lasting effects should be mild.

  • Hyper alertness
  • Possible slight “floppy” muscle tone
  • Overly brisk reflex responses
  • Strong Moro (startle) reflex
  • Dilated pupils (mydriasis)
  • Weak or absent suck reflex
  • Trouble sleeping
  • Jittery
  • Fast heart rate
  • Frequent crying

Stage II HIE

Stage II HIE may be either moderate or severe depending on the extent of your baby’s symptoms. Immediate symptoms of Stage II HIE generally last for about two to 14 days and require more medical attention than Stage I HIE.

  • Lethargy
  • “Floppy” muscle tone
  • Difficulty grasping with hands
  • Weak Moro (startle) reflex
  • Weak or absent suck reflex
  • Weak startle reflex
  • Trouble breathing/apnea
  • Seizures
  • Constricted pupils (miosis)
  • Abnormal brain wave activity


Stage III HIE is the most severe, and babies with Stage III HIE will be much less active and engaged.

  • Unresponsive, coma-like state
  • “Floppy” muscle tone all over
  • No response to physical stimuli or Moro reflex
  • Extreme difficulty with breathing
  • Absent neonatal reflexes, like sucking/swallowing
  • Vision problems
  • Dilated, fixed, or unresponsive pupils
  • Treatment-resistant seizures that begin/increase after 24-48 hours
  • Irregular heartbeat
  • Poor blood pressure
  • Irregular brain waves

The Moro reflex is a motion that may be familiar to you as a jerky motion you experience sometimes when falling asleep. It is the feeling of falling you get when almost asleep followed by a reflex to “catch” yourself. In babies, this is something that happens, too, and its presence is a positive indicator of less severe neurological effects, at least to some degree.

What Are the Long-Term Effects of Hypoxia on the Brain?

The most severe outcome of a hypoxic brain injury is death, but a large percentage of surviving children will have significant neurological symptoms. Babies with HIE are at risk for cerebral palsy and other severe neurological impairments:

  • Cognitive impairment
  • Neurodevelopmental delay
  • Motor impairment
  • Developmental delay
  • Epilepsy
  • Speech/language impairment
  • Cerebral Palsy
  • Vision/hearing loss

Unfortunately, brain injuries are as complex as brains themselves, and two stages of injury can happen.

  1. The first stage is the damage that occurs within a matter of minutes of oxygen deprivation. Cells do not get enough oxygen, and they begin to die.
  2. The second stage is called “reperfusion injury,” and it can last for weeks. This stage happens after treatment begins when the brain is already receiving normal levels of blood flow and oxygen. Studies suggest that symptoms of CP are closely related to this stage of injury.

In fact, HIE is one of the more common causes of congenital cerebral palsy, a term that refers to CP that is caused by injury before or during birth. CP and other neurological impairments may not always be evident right away, but as children get older and more developed, impairments may become clearer.

Regardless of their Sarnat stage, children with a history of HIE may experience life-long effects of their hypoxic injury. In a number of mild cases, the long-term effects of HIE might even go largely unnoticed. However, researchers are digging deeper to understand the outcomes of HIE, and they have found that children with a history of mild HIE seem to have poorer cognitive outcomes than children with no history of HIE. In fact, the children who had mild HIE seem to have the same kinds of lingering effects as children who were diagnosed as newborns with moderate HIE.

Can a Child Recover from Brain Damage from Hypoxia?

Brain damage from a lack of oxygen cannot be reversed. However, therapies are available, such as CP therapies, that can help to address the symptoms and increase your child’s independence and quality of life:

  • Physical therapy
  • Speech therapy
  • Occupational therapy
  • Behavioral therapy
  • Recreational therapy

CP is a neurological disorder, which means that it affects muscle tone, movement, and motor skills. Detecting CP in older babies is relatively clear because it involves making sure that a baby is hitting all developmental milestones on time. The level of care needed and the kinds of treatments most beneficial for your child will depend on several factors:

  • How long your baby went without enough oxygen
  • How low was your baby’s level of oxygen
  • How quickly the right treatment was given

Did Medical Malpractice Cause My Baby’s HIE?

In a number of cases, birth injury or other medical negligence is a direct cause of CP. If you believe that your child’s cerebral palsy was caused by medical malpractice, you may have options for seeking financial compensation under the law. Medical malpractice must meet four specific criteria:

  • The physician owed a duty to provide the patient with a certain standard of care.
  • The physician violated that standard of care.
  • The patient suffered an injury caused by a violation of the standard of care.
  • The patient has experienced damage as a result of the injury: physical, emotional, and/or financial.

You will need to prove that your child’s CP is a direct result of healthcare professionals’ actions, but you do not need to know how to do this alone—that’s where having an experienced CP lawyer to fight on your side is important.

What Kind of Help Is Available for Paying for My Child’s Brain Hypoxia Recovery?

If your child is diagnosed with HIE, and you believe it was caused by a form of medical malpractice, you might be unsure what your next steps should be. HIE treatment and support can be costly and the emotional stress of your child experiencing such an injury can be detrimental to your family’s quality of life. You might consider seeking legal help if you believe your child’s HIE was caused by medical malpractice.

The Cerebral Palsy Family Lawyers at Janet, Janet & Suggs have consulted with over 30,000 families nationwide, using our legal and medical experience to uncover the truth and recover the compensation families deserve. If your child suffered from medical malpractice that led to brain hypoxia injuries, contact the Cerebral Palsy Family Lawyers at Janet, Janet & Suggs today for a free, no-obligation consultation.



Claire Surles, RN
Reviewed by:
Claire Surles, RN
Registered Nurse

Claire comes to JJS after a 10-year career as a labor and delivery nurse. She dedicated her hospital efforts to advocating for families, providing the safest birthing environment possible as Newborn Admission Nurse at UMMC St. Joseph Medical Center in Towson, Maryland. Her passion for helping those who experienced losses at any stage of gestation led to her appointment as Coordinator of the hospital’s ROOTS perinatal loss program. READ FULL BIO

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