Research scientists have examined thousands of expectant mothers, followed them through childbirth, and monitored their children's early neurological development. As a result, they have uncovered certain characteristics, called risk factors, that increase the possibility that a child will later be diagnosed with cerebral palsy:

• Breech presentation. Babies with cerebral palsy are more likely to present feet first, instead of head first, at the beginning of labor.
• Complicated labor and delivery. Vascular or respiratory problems of the baby during labor and delivery may sometimes be the first sign that a baby has suffered brain damage or that a baby's brain has not developed normally. Such complications can cause permanent brain damage.
• Low Apgar score. The Apgar score (named for anesthesiologist Virginia Apgar) is a numbered rating that reflects a newborn's condition. To determine an Apgar score, doctors periodically check the baby's heart rate, breathing, muscle tone, reflexes, and skin color in the first minutes after birth. They then assign points; the higher the score, the more normal the baby's condition. A low score at 10-20 minutes after delivery is often considered an important sign of potential problems.
• Low birthweight and premature birth. The risk of cerebral palsy is higher among babies who weigh less than 2500 grams (5 lbs., 7 1/2 oz.) at birth and among babies who are born less than 37 weeks into pregnancy. This risk increases as birthweight falls.
• Multiple births. Twins, triplets, and other multiple births are linked to an increased risk of cerebral palsy.
• Nervous system malformations. Some babies born with cerebral palsy have visible signs of nervous system malformation, such as an abnormally small head (microcephaly). This suggests that problems occurred in the development of the nervous system while the baby was in the womb.
• Maternal bleeding or severe proteinuria late in pregnancy. Vaginal bleeding during the sixth to ninth months of pregnancy and severe proteinuria (the presence of excess proteins in the urine) are linked to a higher risk of having a baby with cerebral palsy.
• Maternal hyperthyroidism, mental retardation, or seizures. Mothers with any of these conditions are slightly more likely to have a child with cerebral palsy.
• Seizures in the newborn. An infant who has seizures faces a higher risk of being diagnosed, later in childhood, with cerebral palsy.

Knowing these warning signs helps doctors keep a close eye on children who face a higher risk for long-term problems in the nervous system. However, parents should not become too alarmed if their child has one or more of these factors. Most such children do not have and do not develop cerebral palsy.