Postpartum hemorrhage (PPH) is a leading cause of maternal mortality, and its severity has been increasing globally, including in high-income countries. The most common cause of PPH is uterine atony occurring in about 70% of cases. Uterotonic agents, like oxytocin, are key in managing the third stage of labour to prevent PPH. Oxytocin is a short-acting medication and requires frequent dosing, however, carbetocin, a longer-acting analogue that can be administered as a single dose, provides sustained uterotonic activity. Calcium chloride is a readily available, inexpensive medication that has been studied as an adjunct to primary uterotonics due to its role in uterine contractility. A randomized trial found no overall reduction in blood loss with calcium chloride and oxytocin, but a subgroup analysis suggested it may reduce bleeding in cases of uterine atony. This study was conducted in the US where carbetocin is not readily available. The investigators propose a double-blind randomized trial investigating if co-administering calcium chloride with carbetocin during scheduled cesarean deliveries reduces PPH secondary to uterine atony.
Scheduled CD for patients ≥ 37 weeks excluding high risk factors for uterine atony
Neuraxial anesthesia as the primary anesthetic where intrathecal medications are the primary anesthetic
Overdistended uterus due to fetal macrosomia reported on prenatal ultrasound >90th centile or > 4000 gm, multiple gestation, grand multiparity (≥5 births at ≥ 20 weeks gestation), polyhydramnios
History of uterine atony/PPH (documented with blood loss > 2000 ml, blood transfusion, use of surgical methods such as Bakri balloon, B-Lynch sutures, uterine artery ligation or embolization)
Obesity with body mass index (BMI) > 40 kg/m2
Placenta previa and/or placenta accreta