The Minimum Effective Dose (ED90) of Prophylactic Oxytocin Infusion During Cesarean Delivery in Patients With and Without Obesity: An Up-Down Sequential Allocation Dose-Response Study

Int J Obstet Anesth. 2024;57:103962. https://doi.org/10.1016/j.ijoa.2023.103962 A leading cause of maternal morbidity and mortality, with uterine atony being the primary factor, is postpartum hemorrhage (PPH). The administration of oxytocin, used as the first-line prophylactic to prevent uterine atony during cesarean delivery (CD), varies in dose, timing, and duration across clinical practices. Lower oxytocin doses are often used to minimize maternal side effects linked to high-dose boluses or empirically titrated infusions. With rising obesity rates and significant pregnancy weight gain, higher oxytocin doses are required for labor induction and augmentation in obese patients. Research indicates obesity may reduce oxytocin-induced myometrial contractility. Despite this, only one study has evaluated the optimal oxytocin dose in patients with a BMI ≥40 kg/m 2 undergoing CD, highlighting a need for more research. The study aims to determine the minimum effective oxytocin infusion dose for adequate uterine tone in obese patients, comparing it with a control group of nonobese patients.