[This post is part of our Knowledge Translation Tuesday series. Guest author Lily Collison, author of Spastic Diplegia — Bilateral Cerebral Palsy, continues the series on her journey with her son and cerebral palsy (CP). Author note: The is the view out over the Atlantic on Sunday as we climbed Knocknarea–the hill I pointed out in last week’s post.]

In coming to terms with our child’s CP diagnosis, we almost always ask the question why? This week I will write about cerebral palsy causes and risk factors. As we will see below, very often no specific cause is identified. This was the case with our son.

The term cause is self-explanatory. The term risk factor can be defined as any attribute, characteristic, or exposure of an individual that increases the likelihood of developing a disease or injury. Causes thus have a stronger relationship with CP than risk factors. Significant deprivation of oxygen to the infant’s brain, for example, is a cause of CP. Preterm birth is a risk factor but not a cause of CP—in other words, not every preterm baby is found to have CP. There are many possible causes of brain injury, including events before and during pregnancy, during birth, or in early infant life. Much is known about the causes and risk factors for CP, but much remains unknown as well. Depending on what you read, you may come across different lists of causes and risk factors for CP.

Causes of CP
Developing fetuses and infants (up to age two to three) can develop CP if they experience brain injury or disruptions in brain development caused by¹:

• Bleeding in the brain before, during, or after birth.
• Infections of the brain, including meningitis or encephalitis.
• Shock—a state in which organs and tissues do not receive adequate blood flow.
• Traumatic brain injuries, such as from a serious car accident.
• Seizures at birth or in the first month following birth.
• Certain genetic conditions.

Risk factors for CP
Risk factors for CP include¹:

• Preterm birth and low birth weight. A typical pregnancy lasts 40 weeks. Babies born before 37 weeks have a greater risk of having CP. The risk increases the earlier a baby is born and the lower the baby’s birth weight. Twins and other multiple-birth siblings are at particular risk because they tend to be born earlier and at lower birth weights.
• Serious illness, stroke, or infection in the mother. CP is more common in children whose mothers:
  – Experience certain viral and bacterial infections and/or high fevers during pregnancy.
  – Have coagulation (clotting) disorders or experience blood clots during pregnancy.
  – Receive excessive exposure to harmful substances during pregnancy.
  – Have thyroid problems, seizure disorders, or other serious health concerns.
• Serious illness, stroke, or infection in the baby. Infants who experience serious illnesses, strokes, or seizures around the time of birth are at greater risk of having CP. Such illnesses might include:
  – Severe jaundice. (Kernicterus is a rare kind of preventable brain damage that can happen in newborns with jaundice.)
  – Seizures during the first 48 hours after birth.
  – Infections of the brain, such as meningitis or encephalitis.
  – Strokes caused by broken or clogged blood vessels or abnormal blood cells.
• Pregnancy and birth complications. For example, not enough nutrition through the placenta or a lack of oxygen during labor and birth. Incompatible blood types between mother and baby.
• Genetic issues.

I will continue with part 2 next week.

¹ Gillette Children’s Specialty Healthcare (2019) What Is Cerebral Palsy? [online].