资料来源与方法本文所用基础资料为道外区卫生防疫站生命统计资料。道外区于1953年开始建立人口、出生、死亡登记制度,主办单位为道外区户籍管理部门和卫生防疫站。住户发生出生、死亡均向当地户口管理机关报告,出生后立即死亡的新生儿亦须报告,并同时登记为一个出生、一个死亡;凡怀孕未满28周 Sources and methods of data The basic data used in this paper are the vital statistics of the Sanitation and Epidemic Prevention Stations in Daowai District. In 1953, Daowai District began to establish a registration system for population, birth, and death. The organizers are household registration management departments and sanitation and anti-epidemic stations in Daowai District. Births and deaths of households are reported to the local household registration authority. Newborns who have died immediately after birth are also required to report and are also registered as one birth and one death; where the pregnancy is less than 28 weeks