The purpose of this study is to evaluate the influence of pre-eclampsia risk screening scheme based on maternal high-risk factors or pre-eclampsia risk assessment and management plan based on placental growth factor (PIGF) detection in the real medical world on the incidence of pre-eclampsia, maternal mortality and severe complications of pre-eclampsia, and to establish appropriate pre-eclampsia risk screening and prevention standards and guidelines for China population, so as to reduce the probability of maternal and fetal death and long-term chronic diseases.