What Commonly Causes Hypoxia in Newborns?

Published on February 19, 2024

The birth of a new baby is a joyous, unforgettable event for every family, but when parents learn their baby suffered hypoxia during or after childbirth, they’re left wondering what the future holds. Despite advances in today’s obstetric care, hypoxia and hypoxic-ischemic encephalopathy (HIE), remain a problem with long-term health impacts for more than two out of every 1,000 children born in the U.S. Around 25 percent of children who survive hypoxia experience adverse long-term effects on their neurodevelopment. Hypoxia remains one of the most serious birth injuries to full-term infants.

What are neonatal hypoxia and hypoxic-ischemic encephalopathy, and what causes it in infants?

What is Hypoxia in In Newborns?

Hypoxia occurs when an infant suffers from oxygen deprivation during the birthing process or after birth. If not immediately addressed, an infant with hypoxia may develop a brain injury due to lack of oxygen to the brain—ischemic encephalopathy. Birth injuries from hypoxia impact the brain and nervous system, resulting in a degree of impairment dependent upon the severity of the injury, but commonly resulting in neurological and developmental problems, including cerebral palsy and intellectual disability. The longer the baby’s brain is deprived of oxygen, the more severe the trauma and impairment. Damage to the brain occurs both from the initial cell death due to lack of oxygen and glucose from reduced blood flow to the brain, and also from later secondary effects when blood flow returns due to oxidative stress, inflammation, and microvascular damage. As cells rupture and die, they release substances that cause further cell death and the formation of scar tissue in the brain.

Cell death, scar tissue, and other impacts from HIE in newborns cause long-term impacts which may include:

• Cerebral palsy
• Deafness
• Impaired intellect
• Developmental delays
• Poor motor skills
• Death

Prompt intervention and treatment minimize the risk of death and disability from hypoxia.

What Are The Risk Factors For Hypoxia?

Birth injuries are the most common cause of hypoxia, sometimes resulting from poor fetal monitoring during labor and delivery or from a medical provider’s lack of prompt action to address an emergency during labor or delivery. Risk factors for an increased likelihood of hypoxia include the following:

• Maternal blood pressure problems—either high or low blood pressure in the mother during pregnancy and childbirth
• Infant heart defects
• Problems with the placenta such as placenta previa or placental abruption
• Uterine problems including rupture
• Umbilical cord injury during labor or delivery
• Cord constriction during birth
• Umbilical cord prolapse
• Impaired maternal blood flow to the placenta
• Maternal pelvic infections
• Shoulder dystocia (delayed delivery due to an infant’s shoulder caught under the pelvic bone
• Fetal stroke

When a doctor fails to recognize and promptly address the causes of infant hypoxia, the impacts on the baby are often severe, with long-term consequences including the risk of death or permanent disability. 

What Are the Signs of Infant Hypoxia?

Both mothers and doctors during pregnancy, labor, and delivery should remain alert to the signs of hypoxia in infants. Doctors must closely monitor an unborn infant’s heart rate during labor and delivery. A slow, irregular, or erratic heartbeat in an infant during the birthing process or after delivery is a sign that the infant isn’t getting the necessary oxygen. When a medical provider detects these common signs and reacts promptly with interventions, it prevents serious injury. Common signs of hypoxia in infants include the following:

• Reduced or lack of fetal movement before or during labor
• Paleness, or a gray or blue tone
• Low Apgar score
• Difficulty breathing or requiring respiratory support
• Lethargy
• Fatigue
• Poor or weak muscle tone
• Poor reflexes
• Weakness
• Lack of crying
• Acidosis (higher than normal level of acid in the blood)
• Presence of meconium in the amniotic fluid
• Failure to nurse or take formula
• Seizures
• Organ failure

Infants who suffer brain injury from hypoxia may appear floppy or stiff. Some infants may cry excessively while others may not cry at all.

Diagnosing Hypoxic-Ischemic Encephalopathy (HIE)

Doctors may suspect HIE immediately after birth when an infant presents with any of the above symptoms. If medical providers suspect HIE, they must request diagnostic testing.  Diagnostic tests for HIE include:

• Blood tests to determine the infant’s oxygen level and levels of acid, calcium, electrolytes, and enzymes
• Ultrasound of the head to look for fluid buildup or bleeding
•  Lumbar puncture to withdraw and test cerebrospinal fluid for infection
• Electroencephalography (EEG) to measure brain activity
• MRI of the brain at four to seven days after birth to check for/measure damage

If a newborn exhibits signs of hypoxia but a doctor fails to order diagnostic testing and the result is brain damage to the child, it’s medical malpractice and a Phoenix perinatal hypoxia lawyer can help.

Are There Treatments for Infant Hypoxia?

Preventing brain damage by promptly recognizing early signs of hypoxia during childbirth and providing immediate emergency medical intervention is the best way to minimize or eliminate the risk of brain injury. However, after a child has suffered hypoxia, prompt action on the part of medical providers helps to minimize or mitigate the damage. 

The most promising treatment for newborns suffering from HIE is therapeutic hypothermia (TH), or brain cooling to minimize cell damage and brain injury. In order to be effective, this treatment must occur within six hours of the HIE event, meaning doctors must promptly recognize and address HIE with cooling therapy. Cooling an infant’s brain down to a level below homeostasis minimizes or prevents the secondary injury caused by oxidative stress and inflammation. Doctors typically apply cooling caps and/or blankets to the infant to lower brain temperature for 72 hours. This slows the metabolic rate and allows the damaged brain cells to recover rather than rupture and cause further damage to surrounding cells. After 72 hours, the baby must be warmed slowly to prevent reperfusion injury caused by too rapid a restoration of the blood flow. Doctors may also treat hypoxia with anti-seizure medications and respiratory supportive measures.

The sooner doctors apply therapeutic hypothermia to an infant who suffered hypoxia during the birthing process, the better the child’s outcome with a decreased chance of death or severe disability. Failure to promptly provide this preventative therapy to a baby who suffered hypoxia during delivery is medical malpractice.