Prophylactic Intravenous Calcium Gluconate to Decrease Blood Loss at Time of Cesarean Delivery in Pregnant Patients at High Risk for Uterine Atony

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 tocesarean delivery

• Or Scheduled Cesarean Delivery at High Risk for Atonic Bleeding Defined as scheduledCesarean-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 forseizure 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 obstetricianor 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