Is anterior placentation a risk factor for hemorrhage at time of cesarean section?

Anterior placentation is a risk factor for hemorrhage during cesarean section in patients with placenta previa and low lying placenta (1). In the absence of previa and low-lying placenta, it is not known if anterior placenta alone is a risk factor for hemorrhage at time of cesarean delivery. This retrospective cohort study is a secondary analysis of resolved low-lying placenta. We included all patients undergoing cesarean delivery including normal placentation and a history of resolved low-lying and placenta previa a single urban hospital between 2015 to 2019. The primary outcome was postpartum hemorrhage and secondary outcomes were use of uterotonic agents, use of tranexamic acid, and composite of additional procedures to control bleeding, transfusion and ICU admission. Placental location was identified at time of anatomy scan and defined as either anterior or non-anterior location. We compared demographic characteristics using t-tests and chi-square tests as appropriate and estimated differences in outcomes using multivariate logistic regression. 536 patients were included in this secondary analysis, 233 were included in anterior placenta group and 303 in the non-anterior placenta group. Demographic characteristics are shown in Table 1. Anterior placenta was not associated with increased risk of postpartum hemorrhage (aOR 0.80, 95%CI [0.5, 1.3]) after adjusting for age, BMI, IVF pregnancy, parity and prior cesarean delivery (Table 2). Similarly, anterior placenta was not associated with increased use of uterotonics (aOR 0.84, 95% CI [0.5, 1.3]), tranexamic acid (aOR 0.66, 95%CI [0.2, 2.4]), and need for additional procedure, transfusion or ICU admission (aOR 1.03, 95% [0.5, 2.0]). Anterior placenta does not appear to increase the risk for postpartum hemorrhage, increased use of uterotonics, tranexamic acid, and need for additional procedure, transfusion or ICU admission. Further studies are needed to confirm these findings.View Large Image Figure ViewerDownload Hi-res image Download (PPT)