Birth defects is the child before birth, in the womb has occurred on morphology, physiological dysfunction or metabolic defects caused by abnormal morphology differences usually congenital malformations. If there is no brain child, spina bifida, cleft lip, limb abnormalities, physiological functions and metabolic defects often lead to congenital mental retardation (commonly known as "stay", "stupid"), deaf, dumb and other abnormalities.