智能迟滞症是指在胚胎期或出生以后,由于各种原因造成脑发育障碍,表现为智能在普通水平以下,影响学习和社会适应能力的疾病,又称精神发育迟滞症,脑发育迟滞症、智能低下、弱智。本症在国外患率为5.4～8‰,据调查国内约为3‰。男女患病率基本相等,但农村患病率要比城市高得多,城乡患病率比例为1:2.1。智能发育迟滞症的病因比较复杂,概言之有出生前、出生时和出生后 Intellectual Hidrosis refers to the disease in the embryonic or postnatal period, due to various causes of brain development disorders, the performance of the intelligence below normal level, affecting learning and social adaptation of the disease, also known as mental retardation, brain retardation, Intelligent low, mentally handicapped. The disease prevalence rate in foreign countries is 5.4 ~ 8 ‰, according to the survey of about 3 ‰. The prevalence of males and females is roughly the same, but the prevalence in rural areas is much higher than in urban areas, with a prevalence rate of 1: 2.1 in urban and rural areas. The causes of mental retardation more complicated, there is a summary of before birth, at birth and after birth