Risk factors associated with CP are grouped into prenatal, perinatal, and postnatal factors. Prematurity and low birth weight are the two most important risk factors in developed countries with high standards of obstetrical care. Postnatal risk factors additionally play a major role in other countries. A clear association exists between premature delivery and spastic diplegia. Low birth weight increases the risk. Rubella, herpes simplex, toxoplasma, and cytomegaloviruses cross the placenta to infect the fetus and have severe effects on the developing CNS. Eclampsia or other severe maternal illness hypothermia, hypoglycemia of the neonate cause a reduction in the levels of oxygen and nutrients available to the fetus or an increase in the levels of toxins or waste products, adversely affecting the developing CNS. Multiple pregnancies or breech presentation also can increase the risk. Excess of bilirubin resulting from the haemolytic disease of the newborn is clearly associated with CP. Babies who carry these risk factors should be under close supervision by a pediatric neurologist for signs suggestive of neuromotor developmental delay.