Case-control study of thrombophilia patients treated with enoxaparin undergoing cesarean section: Comparison of change in hematocrit, and estimated blood loss

Abstract

UNDERGOING CESAREAN SECTION: COMPARISON OF CHANGE IN HEMATOCRIT, AND ESTIMATED BLOOD LOSS SHAD DEERING, MADHU UPPALATI, CRAIG KESSLER, SUSAN LASHGARI, ANDREA SHIELDS, HELAIN LANDY, Georgetown University, Obstetrics and Gynecology, Washington, District of Columbia, Georgetown University, Hematology, Washington, District of Columbia, Madigan Army Medical Center, Tacoma, Washington OBJECTIVE: Low molecular weight heparin (LMWH) is increasingly used in thrombophilic women during pregnancy with little objective data examining its effect on blood loss with cesarean section. This study evaluates the effect of enoxaparin on operative blood loss in thrombophilic women being anticoagulated with enoxaparin prior to and after cesarean delivery. STUDY DESIGN: 18 women with a documented thrombophilia treated with enoxaparin underwent cesarean delivery. Patients on enoxaparin were scheduled for labor induction or cesarean for obstetric indications 24 hours after their last scheduled dose. Control patients with no history of venous thromboembolism, thrombophilia, or other bleeding disorders were matched for gestational age and indication for cesarean. Demographic information, the time interval between last enoxaparin dose and cesarean, pre and post-operative hematocrit, estimated blood loss (EBL), and the need for transfusion was collected and analyzed. Statistical analysis utilized the Student t-Test, Chi-Square test, or linear regression as appropriate. RESULTS: Mean maternal and gestational ages were 33.8 (G4.6) years and 37.2 (G2.5) weeks respectively. Mean time from last enoxaparin dose to cesarean was 33.1 (G17.3) hours. No difference between thrombophilic and control patients in preoperative hematocrit (36.9 G 4.5% vs. 35.6 G 3.7%, P = .36) or change in hematocrit (5.2 G 2.7% vs. 5.0 G 2.7%, P = .79) were noted. The EBL was greater for enoxaparin patients (705 G 172 mL vs 808 G 269 mL) but this was not statistically significant (P = .18). Only one patient in the thrombophilia group had a decrease in hematocrit of >10% (10.7%) and no patients required transfusion. Regression analysis demonstrated no relationship between the change in hematocrit and either the length of time since the last administration of enoxaparin (P = .81) or dose of enoxaparin (P = .94). CONCLUSION: Planned or indicated cesarean delivery in patients treated with enoxaparin during pregnancy was not associated with increased blood loss or decreased hematocrit compared to normal controls.