Effect of phenylephrine infusion on postpartum blood loss after cesarean delivery: A Placebo-controlled, randomized clinical trial.

Background: Preclinical studies have documented the role of alpha-adrenergic agonists in myometrial contraction. Phenylephrine is frequently used to prevent and treat post-spinal hypotension during cesarean delivery. We hypothesized phenylephrine would reduce postpartum blood loss due to alpha-1 receptor-mediated uterine and vascular smooth muscle contraction.