Factors associated with hemorrhage in cesarean deliveries.

TLDR

A case‑control study was performed to investigate risk factors for hemorrhage in cesarean deliveries. Hemorrhage was defined as a ≥10‑point drop in hematocrit or the need for transfusion; patients with antenatal bleeding were excluded, and each case was matched to three controls with logistic regression used to adjust for covariates. Among 3,052 cesarean deliveries, 6.4% experienced hemorrhage, and significant predictors were general anesthesia (OR 2.94), amnionitis (2.69), preeclampsia (2.18), protracted active phase (2.40), second‑stage arrest (1.90), Hispanic ethnicity (1.82), and a small but significant association with classic uterine incision (OR 1.06); other factors showed no association, and the results can aid in anticipating hemorrhage and planning blood‑bank resources.

Abstract

A case-control study was performed to study risk factors for hemorrhage in cesarean deliveries. Hemorrhage was defined by a pre- to post-delivery hematocrit decrease of 10 points or more or by the need for red-cell transfusion. Patients with antenatal bleeding were excluded. Among 3052 cesarean deliveries, hemorrhage occurred in 196 cases (6.4%). Three controls were matched to each case and multiple logistic regression was used to control for covariance among predictor variables. Factors having a significant association with hemorrhage were: general anesthesia (adjusted odds ratio 2.94), amnionitis (odds ratio 2.69), preeclampsia (2.18), protracted active phase of labor (2.40), second-stage arrest (1.90), and Hispanic ethnicity (1.82). After adjustment for these variables, a classic uterine incision had a small but significant association (odds ratio 1.06) with hemorrhage. Previous cesarean, parity, gestational age, and several other factors had no association with hemorrhage. These data allow one to anticipate hemorrhage in patients at risk and may be useful in planning appropriate use of blood bank resources, including antepartum autologous blood donation.