Abstract: Objective The study aimed to investigate the changes of autologous whole blood during the preservation in the third trimester of pregnancy and to provide theoretical guidance for preoperative autologous blood donationin pregnant women. Methods Twenty-eight late pregnancy women with autologous blood storage in our hospital were enrolled and divided equally into routine anticoagulant group (group 1) and high-anticoagulant group (group 2). At the sane time, 20 cases of conventional anticoagulated female unpaid blood were selected as control. Then we monitored the changes of blood coagulation function, blood viscosity, lactic acid concentration, blood potassium and blood appearance in 3 groups during preservation, and counted the utilization rate of blood in the obstetric group. Results The PT and APTT values of group 1 were significantly lower than control(P<0.05), and FIB concentration was significantly higher than control (P<0.01) at 1 h. During the preservation, compared with the control group, the APTT value and PT value of group 1 were gradually prolonged (P<0.05), EAI value, blood potassium and lactic acid concentration were gradually increased (P<0.05), FIB concentration were gradually decreased (P<0.05), but there was no significant difference between group 2 and the control group (P>0.05). The blood of group 1 showed fine particle agglutination on the 3rd day. There were 18, 11 and 10 bags of blood which showed Particle agglutination phenomenon; in group 1, group 2 and control group, respectively on the 35d.The utilization rate of preoperative autologous blood in obstetric group was 3.6% (1/28). Conclusion The blood of pregnant women in the third trimester is hypercoagulable. Conventional anticoagulated whole blood undergoes a change in blood quality during storage, manifested by increased lactic acid production, potassium concentration and blood viscosity, micro agglutination had occurred on the 3rd day. Increased proportion of anticoagulant during blood preservation can effectively solve this problem.

Key words: Late pregnancy, Preoperative autologous blood donation, Coagulation function