Cerebral palsy is a name given to a group of different nervous system disorders that are present at birth or appear in the first 3 years of life. What these disorders have in common is that the underlying brain damage doesn't get worse over the years. They also all cause some degree of damage in the motor neurons of the brain, affecting coordination and muscle strength.
Overall, cerebral palsy affects somewhere between 1 in 500 and 1 in 1,000 newborns, though some of these are only mildly affected. The risk is highest in premature and underweight babies. The number of new cases of cerebral palsy has actually risen slightly in recent years, partly because better intensive care is keeping more premature babies alive but also because fertility treatments have led to a rise in twin and multiple births, which are more likely to result in a baby with cerebral palsy.
Other risk factors for the development of cerebral palsy include:
- Having a mother who has an infection (e.g., rubella [German measles], toxoplasmosis, herpes, cytomegalovirus) while pregnant.
- Having a mother with an incompatible blood type (Rh incompatibility is an immune problem in which the mother generates antibodies that attack and destroy red blood cells in the fetus, interfering with oxygen supply to the child's organs - it rarely happens in first pregnancies).
- Being exposed to toxic substances in the womb.
- Having a mother with mental retardation, or with a history of thyroid problems or seizure disorders.
- Having a complicated delivery (e.g., breech birth).
- Having a low apgar score (a test carried out several times in the hours after delivery that assigns a score based on heart rate, reflexes, skin colour, and muscle tone).
- Having severe jaundice after birth, especially if left untreated.
- Having seizures as an infant.