What Causes Cerebral Palsy?

There are multiple factors that contribute to cerebral palsy, including lack of oxygen to the baby’s brain during labor and delivery. During labor and delivery, the mother is usually placed on a fetal monitor which monitors and records the baby’s heartbeat. If the baby suffers from a lack of oxygen, then there will be signs of this distress in the baby’s heart tracing as detected by the monitor.

Medical professionals are trained to know the necessary measures to take to relieve the distress. If these measures do not work to correct the lack of oxygen and relieve the distress, then immediate delivery of the baby is necessary to prevent brain injury. If there is a significant delay in recognizing the distress, the prolonged lack of oxygen can result in serious injury to the baby’s brain. This brain injury can later be diagnosed as cerebral palsy. Alternatively, when improperly used, delivery instruments such as forceps and vacuums can result in bleeding into the brain or skull fracture.

Congenital cerebral palsy results from brain injury during a baby’s development in the womb. It is present at birth, although it may not be detected for months. It is responsible approximately 70% of cases identified. An additional 20% are diagnosed with congenital cerebral palsy due to a brain injury during the birthing process. In many cases, the cause of congenital cerebral palsy is unknown.

Possible causes include:

  • nfections during pregnancy have been proven to interfere with appropriate development of the fetal nervous system.  Known contributory infections include:
    • Rubella (German measles)
    • Cytomegalovirus (a herpes-type virus)
    • Toxoplasmosis (an infection caused by a parasite that can be carried in cat feces or inadequately cooked meat).
    • Other infections in pregnant women that may go undetected are being recognized now as an important cause of developmental brain damage in the fetus.
  • Severe jaundice in the infant. Jaundice is caused by excessive bilirubin in the blood and is identified by a yellowing of the skin. The liver functions to filter out bilirubin, however a newborn’s liver may need several days to accomplish this effectively.  In rare case, severe jaundice can result in damaged brain cells. Other rare cases include Rh incompatibility between mother and infant where the mother’s body produces fetal-blood-cell-destroying antibodies which lead to jaundice and eventual brain damage.
  • The physical and metabolic trauma of being born can precipitate brain damage in a fetus whose health has been threatened during development.
  • Severe oxygen deprivation to the brain or significant trauma to the head during labor and delivery.

Some risk factors that increase the possibility that a child will later be diagnosed with CP include:

  • Receiving a low Apgar score 10 to 20 minutes after delivery. An Apgar test is used to make a basic, immediate determination of a newborn’s physical health. For the test, the infant’s heart rate, breathing, muscle tone, reflexes, and color are evaluated and given a score from 0 (low) to 2 (normal).
  • Breech births
  • Vascular or respiratory problems in the infant during birth.
  • A low birth weight (less than 2,500 grams, or 5 lbs. 7.5 oz.) and premature birth (born less than 37 weeks into pregnancy).
  • Physical birth defects such as faulty spinal bone formation, groin hernias, or an abnormally small jaw bone.
  • Being a twin or part of a multiple birth.
  • A congenital nervous system malformation, such as an abnormally small head (microcephaly).
  • Seizures shortly after birth.
  • Bacterial meningitis or viral encephalitis
  • Mothers who had bleeding or severe proteinuria (excess protein in the urine) late in their pregnancy have a higher chance of having a baby with CP, as do mothers who have hyperthyroidism or hypothyroidism, mental retardation, or seizures.