One IV dose of calcium gluconate given before cesarean to reduce bleeding in people at high risk for uterine atony

Phase II, Randomized, Double Blinded, Placebo Controlled Superiority Trial of Prophylactic Intravenous Calcium Gluconate to Decrease Blood Loss at Time of Cesarean Delivery in Pregnant Patients at High Risk for Uterine Atony

Phase 2 Interventional University of Michigan · NCT07217899

This will try a single IV dose of calcium gluconate given around cesarean delivery to see if it reduces blood loss for pregnant people at high risk of uterine atony.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment140 (estimated)
Ages18 Years and up
SexFemale
SponsorUniversity of Michigan Academic / other
Locations1 site (Ann Arbor, Michigan)
Trial IDNCT07217899 on ClinicalTrials.gov

What this trial studies

This phase 2, single-center interventional study at the University of Michigan gives eligible participants a single intravenous dose of calcium gluconate or saline as a comparator at the time of cesarean delivery. Eligible patients are ≥24 weeks with a viable pregnancy and considered high risk for uterine atony either because of prior oxytocin exposure during labor or because a scheduled cesarean meets predefined risk factors (for example multiple prior deliveries, multifetal gestation, placenta previa, high BMI, large fibroids, or prior postpartum hemorrhage). The trial measures measured blood loss at the time of surgery and standard postpartum hemorrhage outcomes such as need for additional uterotonics, transfusion, or surgical interventions. The protocol is FDA IND-exempt and aims to see whether prophylactic IV calcium can reduce atonic bleeding compared with saline.

Who should consider this trial

Good fit: Ideal candidates are English-speaking pregnant people ≥24 weeks undergoing cesarean who are judged high risk for uterine atony (prior oxytocin exposure for labor or scheduled cesarean with one or more listed risk factors).

Not a fit: People who are not high risk for atony, have suspected placenta accreta spectrum, a known allergy to calcium gluconate, or who do not speak English (per protocol) are unlikely to benefit or be eligible.

Why it matters

Potential benefit: If successful, this could lower blood loss during cesarean and reduce the need for extra uterotonics, blood transfusions, or emergency procedures.

How similar studies have performed: This prophylactic IV calcium approach is relatively novel, with limited prior clinical trial data demonstrating benefit for preventing atonic bleeding.

Eligibility criteria

Show full inclusion / exclusion criteria
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

Where this trial is running

Ann Arbor, Michigan

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Blood Loss, SurgicalBlood Loss, PostoperativeUterine AtonyCesarean delivery
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.