716: Predictors of Postpartum Hemorrhage Following Cesarean Delivery: a Model for Calculating Risk of Transfusion

There has been an appreciable rise in the severity of postpartum hemorrhage (PPH) requiring more transfusions in the US. Our objective is to better define patients at greatest risk for severe PPH in order to identify cases for early intervention and monitoring. Using the MFMU Network's Cesarean Registry, we identified cases of PPH defined as 1) non-severe (nsPPH): requiring <4 units pRBCs or 2) severe (sPPH): requiring ≥4 units pRBCs or ICU admission. We used a reference group of no transfusion (no txf). We compared prevalence and severity of hemorrhage associated with maternal, fetal, and socioeconomic risk factors. Multivariate logistic regression models were used to identify predictors that were independently associated with either 1) nsPPH vs no txf, 2) sPHH vs no txf, and 3) any hemorrhage vs no txf. A risk calculator was developed for predicting the need for blood transfusion. We included 13,462 women, with 126 cases of nsPPH (0.9%) and 46 cases of sPPH (0.3%). Hispanic women had an adjusted odds of having both nsPPH and sPPH over twice as high as African Americans. For Asians the adjusted odds ratio is over four times higher, but only for nsPPH. Predictors specific for nsPPH and sPPH are presented in Table 1. For patients with nsPPH, increasing BMI demonstrated a protective effect while with sPPH increasing BMI was a predictor for hemorrhage. Hematocrit and hemoglobin both had a protective effect for transfusion. Using the predictors associated with all hemorrhage, a risk calculator was created to predict hemorrhage outcomes and need for transfusion (p<0.0001, Figure 1). Different risk factors exist predisposing women to non-severe and severe PPH among this large cohort who required cesarean section. Using our data, we were able to create a risk calculator for a prediction model of postpartum hemorrhage requiring a blood transfusion.View Large Image Figure ViewerDownload Hi-res image Download (PPT)