Associated factors of blood transfusion for Caesarean sections in pure placenta praevia pregnancies

This study aimed to evaluate associated factors of blood transfusion for Caesarean sections in pure placenta praevia pregnancies.

A case-control study was conducted among 405 pregnant women with placenta praevia who underwent Caesarean delivery between August 2004 and December 2013. 135 of the women received blood transfusions. Another 270 women who did not receive any blood transfusion were randomly selected and served as controls. Maternal demographic data, reproductive history, antepartum profiles and obstetric outcomes were compared between the two groups.

Women in the case group were significantly more likely to be multiparous, deliver at a gestational age of less than 37 weeks, have a prior Caesarean delivery, experience preoperative bleeding and anaemia, and have major and anterior placenta praevia (p < 0.05). Multivariate analysis demonstrated that significant, independently associated factors of blood transfusion were: previous Caesarean section (adjusted odds ratio [OR] 2.30, 95% confidence interval [CI] 1.36-3.90), anterior placenta praevia (adjusted OR 2.30, 95% CI 1.15-4.60), major placenta praevia (adjusted OR 2.39, 95% CI 1.34-4.22), preoperative bleeding of more than 250 mL (adjusted OR 6.11, 95% CI 2.35-15.90), preoperative anaemia (adjusted OR 2.31, 95% CI 1.34-4.00) and emergency Caesarean section (adjusted OR 2.14, 95% CI 1.08-4.22).

Previous Caesarean section, anterior placentation, major placenta praevia, preoperative bleeding of more than 250 mL, preoperative anaemia and emergency Caesarean section were independent factors that increased the risk of blood transfusion for Caesarean section in pure placenta praevia pregnancies.