Calcium Chloride for Prevention of Blood Loss During Intrapartum Cesarean Delivery

Not Recruiting

Trial ID: NCT05027048


Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality worldwide. Up to 80% of PPH is caused by uterine atony, the failure of the uterine smooth muscle to contract and compress the uterine vasculature after delivery. Laboratory and epidemiological studies show that low extracellular and serum calcium levels, respectively, decrease uterine contractility. A pilot study performed by the investigators supports the hypothesis that intravenous calcium chloride is well tolerated and may have utility in preventing uterine atony. The proposed research will establish the relationship between uterine tone and calcium through a clinical trial with an incorporated pharmacokinetic and pharmacodynamic (PK/PD) study. In a randomized, placebo-controlled, double-blind trial, investigators will establish the effect of 1 gram of intravenous calcium chloride upon quantitative blood loss and uterine tone during cesarean delivery in parturients with high risk of uterine atony. Investigators will concurrently collect serial venous blood samples to measure calcium for PK/PD modeling in this pregnant study cohort. High-quality clinical research and development of novel therapeutics to manage uterine atony are critical to reduce the high maternal morbidity and mortality from PPH.

Official Title

Calcium Chloride for Prevention of Blood Loss From Uterine Atony During Intrapartum Cesarean Delivery (CALBLOC): a Double Blind, Randomized, Placebo Controlled Trial and Nested Population Pharmacokinetic and Pharmacodynamic Analysis

Stanford Investigator(s)

Jessica Rose Ansari

Clinical Assistant Professor, Anesthesiology, Perioperative and Pain Medicine


Inclusion Criteria:

   - Patient had a trial of labor for vaginal delivery prior to cesarean

   - Patient received an oxytocin infusion for labor augmentation or induction prior to

Exclusion Criteria:

   - renal dysfunction with serum Cr >1.0 mg/dL

   - known underlying cardiac condition

   - treatment with digoxin within the last 2 weeks for a maternal or fetal indication

   - treatment with a calcium channel blocker medication within 24 hours

   - hypertension necessitating intravenous antihypertensive medication within 24 hours

   - emergent case in which study participation could in any way impede patient care by the
   judgement of the obstetrician, anesthesiologist, or bedside nurse


drug: Calcium chloride

drug: Saline placebo

Not Recruiting

Contact Information

Stanford University
School of Medicine
300 Pasteur Drive
Stanford, CA 94305
Jessica Ansari, MD