Cerebral palsy is a neurological disorder which typically presents in infancy or early childhood. Those with cerebral palsy exhibit a lack of muscle coordination which affects movements; however, unlike other diseases with similar symptoms cerebral palsy does not progressively worsen over time. Cerebral palsy is the most common cause of muscle disability in children, according to the Centers for Disease Control and Prevention, affecting approximately 1 in 303 children. Cerebral palsy occurs due to abnormalities or damage in the brain usually caused during fetal development or birth. Several factors which affect pregnancy and birth increase the risk of developing cerebral palsy.
Premature Birth
A baby born at 40 weeks is considered a full-term birth. A premature birth describes a baby born less than 37 weeks into the pregnancy. Although the risk of cerebral palsy is greater for premature births, approximately half of babies with cerebral palsy are term, or near-term babies, according to the National Institute of Neurologic Disorders and Stroke.
Low Birth Weight
Low birth weight is associated with premature birth, as the earlier a baby is born the smaller they will be. Babies who weigh less than 5.5 pounds at birth are at an increased risk of developing cerebral palsy, according to MayoClinic.com. The risk increases as the birth weight falls.
Multiple Birth
Babies born as part of a multiple birth, including twins, triplets or more, carry a higher risk of developing cerebral palsy. The risk increases if one of the babies dies.
Rh Incompatibility
In addition to the ABO blood groups, blood types are classified as either Rh positive, meaning the blood agglutinates in the presence of blood typing antiserum, or Rh negative if it fails to agglutinate. During pregnancy the mother's and baby's blood mix together. Rh incompatibility occurs when a mother and baby possess different Rh factors. In this case, the mother's immune system sees the baby's red blood cells as foreign objects and makes antibodies against them. The antibodies attack the baby's blood cells. Mother's who receive prenatal care, especially in the United States, receive treatment to prevent damage to the baby, but those not treated increase the risk of developing complications including cerebral palsy.
Infection
A mother who contracts a viral infection such as toxoplasmosis, rubella or cytomegalovirus during pregnancy increases the risk of the baby being born with cerebral palsy. In response to an infection the mother's body produces cytokines---proteins secreted by immune cells---which then circulate in the blood and brain of the fetus. The cytokines trigger inflammation which can damage the brain and central nervous system of the baby, therefore resulting in cerebral palsy.
Complicated Labor and Delivery
In the past, doctors attributed most cases of cerebral palsy to complicated labor and delivery in which the baby experienced asphyxia, a lack of oxygen. Although asphyxia increases the risk of developing cerebral palsy, a study conducted by the National Institute of Neurologic Disorders and Stroke found that asphyxia caused only 5 to 10 percent of cerebral palsy cases.
