Calculating probability of requiring allogeneic blood transfusion using three preoperative risk factors on cesarean section for placenta previa
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To construct a model to calculating probability of requiring allogeneic blood transfusion on cesarean section (CS) for placenta previa (PP).
A retrospective cohort study involving all 205 patients with PP who underwent CS in our institute. We determined the relationship between allogeneic blood transfusion and nine preoperative factors: (1) maternal age, (2) parity, (3) uterine myoma, (4) previous CS, (5) the placenta covering the previous CS scar (referred to as “scar covering”), (6) degree of previa, (7) ultrasound finding of lacunae, (8) preoperative anemia, and (9) preparation of autologous blood. Independent risk factors of allogeneic blood transfusion were identified by multivariate logistic regression analysis. These significant factors were included in the final model, and, the probability of allogeneic blood transfusion was calculated.
Independent risk factors of allogeneic blood transfusion were scar covering, previous CS without scar covering, and lacunae. These three factors were used to create a predictive model. The model revealed that patients with scar covering and lacunae had the highest probability (0.73), while those with no risk factors had the lowest probability (0.02).
This simple model may be useful to calculate probability of requiring allogeneic blood transfusion on CS for placenta previa.
KeywordsBlood transfusion Cesarean section Placenta accreta Placental lacunae Placenta previa
Fresh frozen plasma
Red cell concentrate
Receiver operating characteristic
Conflict of interest
The authors declare that we have no conflicts of interest regarding this article.
- 4.Yang JI, Lim YK, Kim HS, Chang KH, Lee JP, Ryu HS (2006) Sonographic findings of placental lacunae and the prediction of adherent placenta in women with placenta previa totalis and prior cesarean section. Ultrasound Obstet Gynecol Off J Int Soc Ultrasound Obst Gynecol 28(2):178–182CrossRefGoogle Scholar
- 6.Japan Society of Obstetrics and Gynecology (2008) Placenta previa. In: Japan Society of Obstetrics and Gynecology (ed) Glossary of obstetrics and gynecology, 2nd edn. Kanehara Co. Ltd., Tokyo, p 226–227Google Scholar
- 8.Finberg HJ, Williams JW (1992) Placenta accreta: prospective sonographic diagnosis in patients with placenta previa and prior cesarean section. J Ultrasound Med Off J Am Inst Ultrasound Med 11(7):333–343Google Scholar