Blood transfusion during cesarean section. A 12 years' retrospective analysis.

Transfusional practice over the last 12 years was investigated retrospectively in 1618 women submitted to lower-segment cesarean section. The overall percentage of transfused patients was low (2.4%) and it has become lower in the last four years (1.1%), in concomitance with the development of better knowledge of tissue oxygenation and with the fear of transmitting infectious diseases, factors which have led anesthesiologists to employ blood only when strictly required. Three conditions greatly increased the risk of bleeding: placenta previa, abruptio placentae and coagulation disorders. Previous cesarean section, fetal distress, dystocias and hypertensive disorders of pregnancy did not increase the risk of bleeding and no difference was found between elective and non-elective surgery. Since for elective surgery two units of blood were crossmatched, the crossmatched/transfused ratio (C/T ratio) was very high (60.8/1). To improve blood bank service efficiency, for surgical operations like cesarean section which rarely require blood, it is possible simply to recur to a type and screen (TS) procedure instead of crossmatching blood, but for categories of patients identified as being at high risk of bleeding--placenta previa, abruptio placentae, coagulation disorders--it is advisable to have crossmatched blood available in the operating theatre.