Objective:To explore the quality control of systematic fetal sonography in midtrimester.Methods:2579 cases that had accepte the systematic fetal sonography in midtrimester and gave birth to their babies from May to November of 2007 were involved,And a series of quality control methods weve practiced such as first treatment responsibility,the normalization of examination image saving,checking,reconrding,rechecking,and so on.Results:552 cases didn't finish their first exam because of the factor of fetal posit...