Risk Factors for Cerebral Palsy

Cerebral palsy occurs in approximately 1.2 to 2.5 of every 1,000 infants born alive. Many factors—such as premature birth and serious illnesses—increase an infant’s risk of developing cerebral palsy. In some cases, infants who are born at normal weights and experience no known brain injuries still develop cerebral palsy.
Premature Birth and Low Birth Weight
A normal pregnancy lasts 40 weeks. Babies born before 37 weeks have a greater risk of developing cerebral palsy. The risk increases the earlier a baby is born. Twins and other multiple birth siblings are at particular risk because they tend to be born earlier and at lower birth weights.
The outlook for infants born prematurely or at low birth weights has improved considerably in recent years. Today, many premature infants survive—and new treatments have lowered the incidence of cerebral palsy among them to between 30 and 40 percent.
Serious Illness, Stroke or Infection in Baby
Infants who experience serious illnesses, strokes or seizures around the time of birth are at greater risk of developing cerebral palsy. Such illnesses might include:
Severe jaundice (kernicterus)
Seizures during the 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
Serious Illness, Stroke or Infection in Mother
Cerebral palsy 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
Pregnancy and Birth Complications
Complications of pregnancy and birth—including inadequate nourishment through the placenta or a lack of oxygen during labor and birth—are associated with an increased risk of cerebral palsy. Cerebral palsy also is more common when babies and mothers have incompatible blood types (the mother is Rh positive and the baby is Rh negative, or vice versa).
Genetic and Developmental Problems

Some cases of cerebral palsy are genetic. Genetic conditions can affect development of the brain or other vital organs, such as the heart. Infants with genetic and developmental problems are more likely to develop cerebral palsy.