Could a simple calcium shot cut C-Section bleeding?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * English speaking * Viable Intrauterine Pregnancy, Gestational Age ≥24 weeks * Labor Converted to Cesarean Delivery at High Risk for Atonic Bleeding Defined as: Any exposure to oxytocin infusion for labor augmentation or induction prior to cesarean delivery * Or Scheduled Cesarean Delivery at High Risk for Atonic Bleeding Defined as scheduled Cesarean-Section (CS) plus any one of: 1. \> 4 Prior deliveries 2. General anesthesia 3. Multifetal gestation 4. Polyhydramnios diagnosed by ultrasound within 2 weeks 5. Macrosomia ≥ 4000gms; estimated fetal weight by palpation or by ultrasound 6. Fibroid uterus, defined as: Multiple ≥ 2cm intramural 7. Any history of prior Primary postpartum hemorrhage (PPH) 8. Platelets \< 100,000 (but \>50,000 9. Placenta Previa 10. Body Mass Index (BMI) ≥ 40 Exclusion Criteria: * Non-English speaking * Antenatal suspicion for placenta accreta spectrum * History of allergic reaction to Calcium Gluconate * Patients with hypertensive disorder of pregnancy receiving Magnesium Sulfate for seizure prophylaxis * Underlying Renal Disease defined as Cr\>1.0 * Known underlying cardiac condition * Cardiac glycosides (Digoxin) within two weeks for maternal or fetal indication * Treatment with a calcium channel blocker medication within 24 hours of screening * Hypertensive disorder necessitating intravenous antihypertensive medication within 24 hours of screening * Emergent case where study participation could impede care (judgement of obstetrician or anesthesiologist) * Known hypercalcemia * Concurrent use of any drugs that may cause hypercalcemia including 1. Vitamin D 2. Vitamin A 3. Thiazide Diuretics 4. Calcipotriene 5. Teriparatide * Ceftriaxone within 48 hours of screening * Total Parenteral Nutrition (TPN) within 48 hours of screening * Known Coagulopathy International Normalized Ratio (INR) ≥ 1.5 * Vaginal delivery