3Qureshi,Inafuku K,Qshima,et al.Ultrasonographic evaluation of lower uterine segment to predict the integrity and quality of cesarean scar during pregnancy:a prosepective study.Tohoku J Exp Med,1997,183:55 ~ 65.
4Saldana L,Schulman H.Management of pregnancy after cesarean section.Am J Obstent Gynecol,1979,135:555.