Risk Factors for Predicting Blood Transfusion in Caesarean Section in Hong Kong: Is Type and Screen Necessary for All?

Abstract

Objective: Routine preoperative blood group typing and antibody screening (type and screen) is performed for all patients who undergo Caesarean delivery in our unit in preparation for blood transfusion. There are no objective local data to support such practice. This study aimed to examine the risk factors for blood transfusion following
Caesarean section at a local obstetrics and gynaecology unit in Hong Kong and review the need for universal blood type and screen in patients who underwent Caesarean section.
Methods: This was a retrospective cohort of all deliveries in United Christian Hospital, Hong Kong within a 3-year period from 1 January 2012 to 31 December 2014. Data on demographics, parity, previous Caesarean section/uterine scar, multiple pregnancy, antenatal complications (including anaemia, gestational hypertensive disorders, placenta praevia, placental abruption), and outcomes (postpartum haemorrhage and blood transfusion) were retrieved via the obstetrics clinical information system database.
Results: A total of 119 (3.7%) patients required intraoperative or postoperative transfusion. Univariate analysis showed that the incidence of advanced maternal age, preterm delivery, emergency Caesarean section, multiple pregnancy, as well as presence of placenta praevia and placental abruption were significantly higher in the transfusion group compared with the controls, whereas more patients had previous Caesarean section in the latter group. Multiple pregnancy (odds ratio=3.71), emergency Caesarean section (odds ratio=1.79), placenta praevia (odds ratio=9.64), and placental abruption (odds ratio=6.85) remained statistically significant factors associated with the need for blood transfusion after multivariate regression analysis. A predictive model using these four risk factors gave a sensitivity of 80.6%, specificity of 39%, positive predictive value of 4.8%, and negative predictive value of 98%.
Conclusion: The majority of patients who underwent Caesarean section did not require blood transfusion. Selective type and screen is feasible and safe and can be reserved for patients with specific risk factors.