4AbouZahr C. Global burden of maternal death and disability[J]. Br Med Bull, 2003,67:1-11.
5Preventing infant death and injury, during delivery. Sentinel Event ALERT No. 30. Joint Commission on Accreditation of Healthcare Organizations. Available at : http ://www. jointeommission. org/SentinelEvents/Sentinel EventAlert/sea_30. htm. Retrieved June 12, 2006.
6Chesley LC. Plasma and red cell volumes during pregnancy[J]. Am J Obstet Gynecol, 1972,112:440-450.
7Pritchard JA, Baldwin RM, Dickey JC, et al. Blood volume changes in pregnancy and the puerpefium[J]. Am J Obstet Gynecol, 1962,84 : 1271-1282.
8Clark SL, Yeh SY, Phclan JP, et al, Emergency hysterectomy for obstetric hemorrhage[J]. Ohstet Gynecol, 1984,64: 376- 380.
9Dildy GA, Paine AR, George NC,et al. Estimating blood loss: can teaching significantly improve visual estimation? [J]. Obstet Gynecol,2004, 104:601-606.
10Combs CA, Murphy EL, Laros RK Jr. Factors associated with postpartum hemorrhage with vaginal birth[ J]. Obstet Gynecol, 1991,77:69-76.