What are the risk factors for cerebral palsy?

Some events or medical problems during pregnancy can increase the risk of congenital cerebral palsy. These risk factors include^1,2:

• Low birth weight or preterm birth. Infants born preterm (defined as before 37 weeks of pregnancy) and infants who weigh less than 5.5 pounds at birth are at greater risk of cerebral palsy than are early term (defined as 37 weeks to 38 weeks of pregnancy) and full-term (defined as 39 weeks to 40 weeks of pregnancy) infants and those who are heavier at birth. The earlier the birth and the lower the infant’s birthweight, the greater the risk.
• Multiple gestations. Twins, triplets, and other multiple births are at higher risk of cerebral palsy. The risk is also greater for an infant whose twin or triplet dies before or shortly after birth.
• Infertility treatments. Infants born from pregnancies resulting from the use of certain infertility treatments are at higher risk for cerebral palsy than are infants born from pregnancies not related to infertility treatments. Much of this increased risk may be due to the fact that infertility treatments are more likely to result in preterm delivery and multiple gestations.
• Infections during pregnancy. Toxoplasmosis, rubella (German measles), cytomegalovirus, and herpes can infect the womb and placenta, leading to brain damage in the fetus.
• Fever during pregnancy. Sometimes fever in the mother during pregnancy or delivery can lead to brain damage in the fetus, resulting in cerebral palsy.
• Blood factor between mother and fetus does not match. Those who have a certain protein found on red blood cells—abbreviated Rh—are Rh positive; those who do not have the protein are Rh negative. If a mother’s Rh factor is different from that of the fetus, her immune system may attack the blood cells of the fetus, including blood cells in the brain, which can lead to brain damage.
• Exposure to toxic chemicals. If a mother is exposed to a toxic substance, such as high levels of methyl mercury (found in some thermometers and in some seafood), during pregnancy the fetus is at higher risk of cerebral palsy.
• Maternal medical conditions:
  • Abnormal thyroid function
  • Intellectual and developmental disability
  • Too much protein in the urine
  • Seizures
• Complicated labor and delivery. Infant heart or breathing problems during labor and delivery and immediately after birth increase the risk of cerebral palsy.
• Jaundice (pronounced JAWN-dis). Jaundice, which causes an infant’s skin, eyes, and mouth to turn a yellowish color, can be a sign that the liver is not working normally. Jaundice occurs when a substance called bilirubin (pronounced BIL-uh-roo-bin) builds up faster than the liver can clear it from the body. This condition is common and is usually not serious. However, in cases of severe, untreated jaundice, the excess bilirubin can damage the brain and cause cerebral palsy.
• Seizures. Infants who have seizures are more likely to be diagnosed with cerebral palsy later in childhood.

Some risk factors for acquired cerebral palsy are²:

• Infancy. Infants are at greater risk than older children for an event that causes brain damage.
• Preterm or low birthweight. Children born preterm or at a low birthweight have a higher risk for acquired cerebral palsy.
• Not getting certain vaccinations. Childhood vaccinations can prevent brain infections that can cause cerebral palsy.
• Injury. Not taking certain safety precautions for infants or lack of adult supervision can lead to injury that can cause cerebral palsy.