Effect of Increased BMI on Efficacy of Labor Analgesia

Inclusion Criteria: * Age \> or equal to 18 years * BMI ≥ 40 kg/m² * Gestational age ≥ 28 weeks Exclusion Criteria: * Age \< 18 years * BMI \< 40 kg/m² * History of venous thromboembolism or arterial disease (e.g., DVT, PE, angina, MI, or stroke) * Severe active lung, cardiovascular, renal, or liver disorders; autoimmune disease; or hemoglobinopathies * Hereditary or acquired thrombophilia (e.g., Factor V Leiden mutation or antithrombin deficiency) * In utero fetal demise (IUFD) * Failed operative vaginal delivery * Cesarean for the second twin or multiple pregnancies (triplets or higher) * IVF pregnancy * Intraoperative bleeding\>1500mL * Emergency cesarean section (Category I) * Presence of large uterine fibroid ≥10 cm.