Calcium Carbonate to Augment Labor Contractions (CALC)

October 21, 2025 updated by: Weill Medical College of Cornell University
The investigators think that calcium carbonate can act as an assistive medication to improve contractions during labor.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study plans to study the acceptance and safety of using calcium carbonate as an medicine to help the labor induction process. The study aims to find if the use of calcium carbonate will lead to better labor contractions and increase the percentage of vaginal deliveries and improve delivery outcomes.

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • New York
      • New York, New York, United States, 10065
        • Recruiting
        • Weill Cornell Medicine
        • Principal Investigator:
          • Moeun Son, MD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 18 years or older
  • Nulliparas (no prior pregnancy lasting 20 weeks or greater of gestation)
  • Gestational age above 36 weeks, at enrollment
  • Present for induction or augmentation of labor inclusive of medical indication, elective induction at greater than 39 weeks' gestation, trial of labor after cesarean
  • Singleton gestation (a multiple gestation reduced to a singleton, either spontaneously or therapeutically, before 14 0/7 weeks of gestation is acceptable)
  • Ability to give informed consent
  • Planned to undergo initiation of oxytocin infusion by their maternity care provider

Exclusion Criteria:

  • Unable to understand or read English
  • Presence of tachysystole (defined as more than 5 contractions in 10 minutes averaged over 30 minutes), recurrent variable or late fetal decelerations, and bradycardia in the prior 30 minutes before enrollment
  • Non-vertex presenting fetus at enrollment
  • Planned for cesarean delivery or contraindication to labor by institutional policy (e.g., placenta previa, vasa previa, active genital herpes infection, previous transmural myomectomy)
  • Multi-fetal gestation (twins, triplets, and higher order multiples)
  • Known contraindication to taking calcium carbonate including renal calculus, high urine calcium levels, elevated serum calcium, low serum phosphate, achlorhydria, or suspected digoxin toxicity.
  • Deliveries with fetal chronic and/or pregnancy-related conditions, IUFD (Intra Uterine Fetal Death) or premature < 36 weeks of gestation.
  • Major fetal anomaly suspected prenatally (defined as a fetal anomaly with anticipated neonatal intensive care unit admission)
  • Suspected alloimmunization (given the increased likelihood for anticipated neonatal intensive care unit admission)
  • Known severe fetal growth restriction (estimated fetal weight <3rd percentile) or abnormal umbilical artery Doppler studies (given the increased likelihood for anticipated neonatal intensive care unit admission)
  • Participation in another interventional study that influences management of labor and delivery or perinatal morbidity or mortality
  • Known allergic reactions to synthetic oxytocin intravenous solution or to Calcium Carbonate
  • Significantly impaired consciousness or executive function (e.g., intubated or sedated)
  • Patients treated with calcium channel blockers such as nifedipine or magnesium.
  • Chronic renal failure and hyperphosphatemia.
  • Inability to tolerate oral intake (i.e., nausea/vomiting)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Pitocin
Control group will receive only the standard-dose synthetic oxytocin (Pitocin) alone for labor induction or augmentation.
Drug: Standard Dose Synthetic Pitocin
The participant will receive thestandard-dose synthetic oxytocin for labor induction or augmentation.
Experimental: Calcium Carbonate with Pitocin
Participants will start an oral calcium carbonate regimen at the same time as initiating synthetic oxytocin (Pitocin) infusion.
Drug: Standard Dose Synthetic Pitocin
The participant will receive thestandard-dose synthetic oxytocin for labor induction or augmentation.
Drug: Calcium Carbonate 500 MG
Calcium Carbonate 500mg, orally, every 4 hours.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants Consented
Time Frame: Day 0
RedCAP is used to track the consent rates to determine the feasibility of a larger randomized controlled trial.
Day 0
Number of Participants Enrolled
Time Frame: Day 0
RedCAP is used to track the enrollment rates to determine the feasibility of a larger randomized controlled trial.
Day 0
Number of Participants that complete the Intervention as prescribed (Adherence)
Time Frame: During hospitalization, approximately 5 days
RedCAP is used to track the adherence rates to determine the feasibility of a larger randomized controlled trial.
During hospitalization, approximately 5 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Duration of Labor (minutes)
Time Frame: Approximately 5 days, length of hospitalization
Approximately 5 days, length of hospitalization
Mode of Delivery
Time Frame: Approximately 5 days, length of hospitalization
Vaginal Delivery, Operative Delivery, or Cesarean Section
Approximately 5 days, length of hospitalization
Number of Postpartum Hemorrhages
Time Frame: Approximately 5 days, length of hospitalization
Postpartum Hemorrhage as defined as estimated blood loss of over 1000mL.
Approximately 5 days, length of hospitalization
Number of Treatment Related Adverse Events
Time Frame: Approximately 6 weeks after delivery
Approximately 6 weeks after delivery
Neonatal health (APGAR Score)
Time Frame: Approximately 5 days, length of hospitalization

APGAR (Activity, Pulse, Grimace, Appearance, Respiration). A normal APGAR score ranges from 8-10. An abnormal score ranges from 0-7. Each scoring indicator can range from 0 to 2 points.

Activity (Muscle Tone):

0 Points: Absent

  1. Point: Flexed Limbs
  2. Points: Active

Pulse:

0 Points: Absent

  1. Point: <100 beats per minute
  2. Points: >100 beats per minute

Grimace (Reflex Irritability):

0 Points: Floppy

  1. Point: Minimal response to stimulation
  2. Points: Prompt response to stumulation

Appearance (Skin Color):

0 Points: Blue/Pale

  1. Point: Pink Body, Blue Extremitites
  2. Points: Pink

Respiration:

0 Points: Absent

  1. Point: Slow and Irregular
  2. Points: Vigorous Cry
Approximately 5 days, length of hospitalization
Neonatal health (Cord Blood Gases)
Time Frame: Approximately 5 days, length of hospitalization

Normal Ranges Arterial pH: 7.20 - 7.30 Venous pH: 7.25 - 7.35 Base Excess: -8 to -2 mmol/L

Abnormal Ranges pH < 7.0 (Arterial and Venous) Base Excess < -16 mmol/L (Arterial and Venous)

Abnormal Ranges indicate potential neonatal hypoxia or acidemia.
Approximately 5 days, length of hospitalization
Maternal Health (Number of Subject who experience PostPartum Fever)
Time Frame: Approximately 5 days, length of hospitalization
Approximately 5 days, length of hospitalization
Practicality of Administering Calcium Carbonate, as measured by number of subjects who were administered the total prescribed intervention
Time Frame: Approximately 5 days, length of hospitalization
Approximately 5 days, length of hospitalization
Race
Time Frame: Day 0
White, Black or African American, Asian, More than One Race/Other, Unknown/Not Reported
Day 0
Ethnicity
Time Frame: Day 0
Hispanic, Non-Hispanic, Unknown/Not Reported
Day 0

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Weill Medical College of Cornell University

Investigators

  • Principal Investigator: Moeun Son, MD, Weill Medical College of Cornell University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 18, 2024

Primary Completion (Estimated)

December 1, 2025

Study Completion (Estimated)

December 1, 2025

Study Registration Dates

First Submitted

August 28, 2024

First Submitted That Met QC Criteria

August 29, 2024

First Posted (Actual)

August 30, 2024

Study Record Updates

Last Update Posted (Estimated)

October 23, 2025

Last Update Submitted That Met QC Criteria

October 21, 2025

Last Verified

October 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 24-07027775

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

This is a small pilot study.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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