Predisposing factors for massive hemorrhage during Cesarean section in patients with placenta previa

To investigate whether maternal history and ultrasound findings can be predictors for massive hemorrhage during Cesarean section in patients with placenta previa and adherence of the placenta.

We reviewed 127 singleton pregnancies with placenta previa. Maternal history, antenatal ultrasound findings of the placenta, including location, presence of placental lacunae, lack of a clear zone, presence of sponge-like findings of the cervix and presence of a marginal sinus in cases of placenta previa were reviewed retrospectively, and their association with amount of bleeding during Cesarean section was analyzed.

Logistic regression analysis revealed that advanced maternal age (odds ratio (OR), 5.4; 95% CI, 1.8-16.4), previous Cesarean section (OR, 20.4; 95% CI, 4.0-105.2) and sponge-like findings in the cervix (OR, 5.6; 95% CI, 1.8-17.0) were associated with massive bleeding (> 2500 mL). Placental adherence occurred in five cases and was more frequent in cases where the placenta was located at the site of the scar of a previous Cesarean section (OR, 123.1; 95% CI, 4.5-3395.2) and where there was lack of a clear zone (OR, 48.0; 95% CI, 3.8-604.7).

Advanced maternal age, previous Cesarean section and presence of sponge-like findings in the cervix are risk factors for massive bleeding during Cesarean section in cases of placenta previa, regardless of whether placental adherence is present. Placental location on the scar of a previous Cesarean section and lack of a clear zone are risk factors for placental adherence. When these findings are identified preoperatively, management should be tailored accordingly.