Risk Factors Associated with Cerebral Palsy

Cerebral palsy (CP) is a commonly-diagnosed neuromuscular disorder that affects muscle control and tone in children. According to the Centers for Disease Control and Prevention (CDC), around 1 in 323 children are affected by either congenital or acquired CP. Though researchers understand that CP is caused by abnormalities in a baby’s brain development, the exact triggering mechanism is still a mystery. Nevertheless, doctors and scientists have identified many of the risk factors associated with CP.

Risk Factors for Congenital CP

Congenital cerebral palsy is caused by damage to a baby’s brain that happens either before or during birth. Per the CDC, congenital CP accounts for between 85% and 90% of all cases. Though the exact causes of CP are not always clear, there are certain risk factors that increase its occurrence in newborns.

Keep in mind that risk factors are not the same thing as causes. In medical parlance, risk factors are conditions or situations that may increase the possibility that a baby may be affected by a disability or medical condition. Risk factors do not guarantee the onset of CP or any other birth injury.

Low birthweight: Infants that weigh less than 5.5 pounds at birth, especially those that weigh under 3 pounds, 5 ounces, are more likely to have CP than babies who weigh over 5.5 pounds at birth.

Premature birth: Babies who are born three weeks or more before the 40th week of pregnancy are considered premature or preterm. Though all preterm babies are at risk of having congenital CP, those who are delivered before the 32nd week of pregnancy are more vulnerable. Though modern neonatal intensive care has increased survival rates of preterm babies, their underdeveloped bodies are more likely to suffer from medical conditions that cause CP and other disabilities.

Multiple births: If a mother is expecting twins, triplets, or more babies in a multiple birth situation, at least one infant is at risk of having CP. The risk increases if the baby’s twin or triplet dies before or shortly after birth. Doctors believe that in at least some of these cases, babies in multiple births are born prematurely.

Assisted reproductive treatments (infertility treatments): According to the CDC, mothers who undergo infertility treatments are at a higher risk of having multiple births. As previously mentioned, twins and other multiples tend to be born before the 40th week of pregnancy and weigh less than 5.5 lbs.

Infections during pregnancy: Per the Mayo Clinic, there are several infections that increase the possibility of an infant having congenital CP. These infections include:

  • Bacterial meningitis, which triggers an inflammation of the membranes around the baby’s brain and spinal cord, and
  • Viral encephalitis, another inflammation of membranes that surround an infant’s brain and spinal cord. This inflammation is caused by any of several viruses, including those of the herpes group and insect-borne arboviruses. 

Jaundice and kernicterus: Jaundice is the yellowing of the skin and sclera that occurs when too much bilirubin builds up in a baby’s body. When high levels of bilirubin are present in a newborn’s system, the skin and whites of the eyes (sclera) take on a yellow shading. Per the CDC, if a severe case of jaundice is not treated quickly, it often results in a more serious condition called kernicterus.

Kernicterus, in turn, may cause cerebral palsy and other medical complications. On occasion, blood type and Rh factor differences between mother and infant may trigger cases of severe jaundice. In such cases, jaundice occurs as a result of faster-than-normal breakdowns of red blood cells in the infant’s circulatory system.

Medical conditions of the mother: Women who have Down’s syndrome or other intellectual disorder, suffer from seizures, or have thyroid issues are a bit more at risk of having a baby with congenital CP.

Per the Mayo Clinic, pregnant women with certain health problems or infections have significantly higher risks of having an infant with CP. These include:

  • German measles (rubella)
  • Chickenpox (varicella)
  • Cytomegalovirus
  • Toxoplasmosis
  • Syphilis
  • Exposure to toxic substances

Birth complications: Complications during labor or delivery that disrupt a baby’s oxygen supply can cause CP. Placental detachment, uterine rupture, and umbilical cord problems are common birth complications associated with diminished or disrupted oxygen issues. 

Risk Factors for Acquired CP

According to the CDC, acquired cerebral palsy occurs in a smaller number of cases. It is caused by brain damage that occurs 28 days or more after a baby’s birth. Acquired CP is the result of physical injuries to the infant’s brain. These injuries may include head trauma or viral and bacterial infections.

The most common causes of acquired CP are:

  • Cerebral blood flow problems, including fetal strokes, sickle cell disease, or undetected heart defects that adversely affect the brain’s blood supply
  • Traumatic head injuries, such as those caused by a car accident, a dropped infant, or instances of child abuse that include shaking a baby violently
  • Infections, including meningitis or encephalitis, that cause inflammations in an infant’s central nervous system

Acquired CP is associated with many risk factors that are associated with congenital CP. The only major difference is the time frame in which babies are affected by the condition.

Per the CDC, these are the main risk factors for acquired cerebral palsy:

Infancy: Newborns and toddlers are more likely to have acquired CP than children older than 3 years

Premature birth or low birthweight: Babies who weigh less than 5.5 lbs or are born during or before the 37th week of pregnancy are more likely to acquire CP.

Brain infections: As noted earlier, viral or bacterial infections that inflame an infant’s central nervous system can cause brain damage that results in acquired cerebral palsy.

Injury: Physical trauma, such as that caused by a fall from heights, car accident, or child abuse, is a risk factor in cases of acquired CP.

Remember, just because a risk factor exists, it doesn’t automatically mean that a baby will have cerebral palsy. Risk factors are indications of increased possibilities, not absolute certainties.

It is impossible to eliminate every risk factor associated with the onset of cerebral palsy and other birth injuries, even for the most proficient health care professionals. However, they can be reduced if doctors closely monitor the health of expectant mothers and their unborn babies, especially before the third trimester of a pregnancy. In addition, most birth injuries can be avoided if physicians do not make poor decisions before, during, or after labor or delivery.