Résumé
Objective Preoperative autologous blood donation(PABD) can reduce the demand of allogeneic blood transfusion and its safety in obstetrical application has been proved.The article aimed to explore the effects of PABD on reducing allogeneic blood transfusion in pregnant women with placenta previa and the optimal PABD volume for implanted placenta.Methods Retrospective analysis were made on 156 cases with placenta previa hospitalized in our hospital from January 2015 to April 2016, including 78 cases with placenta implantation.According to the volume of PABD, the cases were classified into no PABD group, 300~400mL PABD group, and 600ml PABD group.Data of postpartum hemorrhage volume and allogeneic blood transfusion after delivery were collected to analyze the effectiveness of PABD in reducing the need for allogeneic blood transfusion during pregnancy.Results The hemorrhage volume during the delivery of all 156 patients with placenta previa was 230-5670mL (median 985ml), the rate of severe postpartum hemorrhage (PPH) was 49.4% (77/156), and the rate of allogeneic blood transfusion was 33.3% (52/156).In patients who had no PABD, the rate of allogeneic blood transfusion was 48.2% (40/83).However, this rate dropped down to 16.4% in PABD patients (12/73)(χ2=17.624,P<0.001).The rate of allogeneic blood transfusion in patients was different according to the situation of placenta planting, 43.3% in patients with no placenta plantingand 53.8% in patients with placenta planting.600ml autologous blood could meet all the needs for blood transfusion if there was no placenta implantation.300-400mL PABD could meet the needs of more than 80% patients.11.2%-13.3% of ABD patients might need allogeneic blood transfusion in addition to autologous blood.However, the amount of allogeneic RBC and FFP per capita reduced.Conclusion Patients with placenta previa is in high risk of PPH and PABD can improve their medical safety by reducing the rate and volume of the allogeneic blood transfusion.The strategy of 300-400mL PABD during pregnancy are recommended if there is no contraindication.