Down＇s综合征占所有智力障碍(智商<55)学龄儿童的1/3—1/4。近年来,由于开展产前诊断和高龄孕妇选择性流产,患儿出生率有所下降。作者对苏格兰西部地区所住人群1975—1994年的Down＇s综合征进行预测,评价了产前诊断计划及终止妊娠的大致费用与经济效益之间的关系。以每5岁划分妇女年龄组,40岁以上妇女组其患婴出生平均每年550人,(每年变化不大),35—39岁组为1,780—2,340人/年。20年后,35岁以上妇女所生婴儿占总出 Down’s syndrome accounts for 1/3 to 1/4 of all mental disorders (<55) in school-aged children. In recent years, due to prenatal diagnosis and selective abortion for older pregnant women, the birth rate has declined. The authors predict Down’s syndrome during the period 1975-1994 of the population living in the western part of Scotland, and evaluate the relationship between the estimated cost and economic benefits of the prenatal diagnosis plan and termination of pregnancy. In the age group of women divided by 5 years old, women aged 40 or above have an average of 550 births per year (not much changed each year), and 1,780-2,340 person-years in the 35-39 age group. 20 years later, babies born to women over the age of 35 account for the total