Risk factors for peripartum blood transfusion in women with placenta previa: a retrospective analysis.

Background: The incidence of placenta previa has been increasing. It is of a great importance to determine the clinical risk factors for peripartum blood transfusion in women with placenta previa in an effort to anticipate cases of severe hemorrhage.
Methods: A total of 129 consecutive cases of placenta previa (64 cases of complete placenta previa and 65 cases of marginal placenta previa), including 43 cases requiring blood transfusion, were retrospectively analyzed. Maternal and neonatal clinical data were examined with univariate and multivariate logistic regression analyses for potential risk factors for peripartum blood transfusion.
Results: The independent risk factors for blood transfusion were maternal age greater than 34 years (adjusted odds ratio [OR]=3.7; 95% confidence interval [CI]=1.5-7.5, p<0.05), history of having undergone dilatation and curettage more than once (adjusted OR=4.8; 95% CI=1.1-26.2, p<0.05), and complete placenta previa (adjusted OR=2.6, 95% CI=1.2-5.9, p<0.05). Body mass index, gravidity, parity, previous cesarean section, antepartum hemorrhage, use of tocolytic agents, gestational age at delivery, preoperative anemia, emergent surgery, birth weight, and Apgar score were not associated with the incidence of blood transfusion.
Conclusion: Risk factors for blood transfusion in women with placenta previa are advanced maternal age, repeat dilatation and curettage, and complete placenta previa. Women with placenta previa who are at risk for blood transfusion should be carefully managed with sufficient preparation for blood transfusion.