Effect of Ephedrine, Phenylepinephrine, and Norepinephrine on Myometrial Contractility in Pregnant People With Type II and Gestational Diabetes During Cesarean Section: An In-vitro Study

March 31, 2026 updated by: Samuel Lunenfeld Research Institute, Mount Sinai Hospital

The goal of this study is to learn about how medication that is used to help treat low blood pressure during a Cesarean delivery (CD) can cause changes to the uterine muscle tissue and its ability to contract, in patients with Type II and gestational diabetes.

Spinal anesthesia administered during elective CD has been known to cause hypotension (low blood pressure) as a side effect during the procedure, and is prevented by administration of vasopressors (medication to raise blood pressure) by the anesthesiologist after the delivery of the baby. Vasopressors treat hypotension by interacting with receptors on blood vessels that increase blood pressure, which can also cause changes to uterine contractility. Inadequate uterine contraction after CD can expose mothers to postpartum hemorrhage (PPH), with diabetic patients displaying a 2.5-times higher risk of PPH.

It is important to understand how vasopressor(s) might affect the uterine contractility of women with Type II and gestational diabetes. Since medication to contract the uterus is also routinely administered at delivery, it is important to study the effect of these drugs in combination. The purpose of this study is to compare uterine contractility patterns and receptor distribution in women with type II and gestational diabetic and control term pregnant patients with administration of vasopressors. This will be done using small uterine tissue samples taken from the incision site following CD, which will then be used for experiments in the laboratory.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The global prevalence of diabetes has increased drastically over the past 20 years, with 1.5 million new cases each year. The prevalence of Type II diabetes in women of childbearing age has shown the greatest increase, in the United States alone rising from 33% in 1990-1998 to 70% in 2020. Additionally, the worldwide rate of cesarean delivery (CD) follows a similar trend. CD procedures can be both elective and emergent, with the rate of elective CD increasing by 30% in Canada since 2001. Neuraxial anesthesia administered during elective CD has been known to induce hypotension as a side effect, which is then countered by administering vasopressors such as epinephrine, norepinephrine, and phenylephrine that act on adrenergic alpha and beta receptors on smooth muscle tissue. However, since these receptors are expressed on the smooth muscle layer of the uterus called the myometrium, vasopressors can elicit changes in myometrial contractility. Inadequate myometrial contractility during CD can expose the mother to postpartum hemorrhage (PPH) which is a leading cause of maternal mortality worldwide.

Additionally, diabetic women undergoing CD are often obese (BMI > 30 kg/m2) or have macrosomia (larger than average baby), which are independent risk factors for PPH. However, there is still a 2.5-fold increased risk in PPH in Type II diabetic patients, even when adjusted for diabetic-associated obesity. Type II diabetics undergoing elective CD also display a reduced contractile profile (as previously explored through in-vitro calcium signaling), which may contribute to their increased risk of PPH. Current research on myometrial contractility shows that throughout the gestational period, the adrenergic receptor subtypes on the myometrial tissue may transition to more pro-contractile phenotypes, which may react differently to administered vasopressors and thus affect induced contractility during CD. Oxytocin, a uterotonic, is the standard treatment for preventing PPH administered immediately after delivery.

There is currently no literature on the unique effects of vasopressors to manage hypotension in obstetric patients who are diagnosed with Type II and gestational diabetes. The increased risk of PPH at CD seen in type II and Gestational diabetics mothers may be due to differences in adrenergic receptor distribution, which have different affinities to the vasopressors administered. No studies thus far have directly explored the role of vasopressors on myometrial contractions in this patient population.

As the use of a standardized vasopressor dosage becomes more routine during elective CD, it is important to understand how this will affect the myometrial contractility of women with Type II and gestational diabetes. The investigators hypothesize that administration of vasopressors in full term pregnant women with type II and gestational diabetes will cause decreased myometrial contractility compared to healthy controls, and that the diabetic tissue will possess a different adrenergic receptor subtype profile compared to controls.

Aim 1: Investigate the differences in myometrial contractility of type II and gestational diabetic vs. control term pregnant patients with administration of vasopressors

Aim 2: Determine the expression of adrenergic receptor subtypes on myometrium of term pregnant type II and gestational diabetic patients

Aim 3: Investigate the difference in downstream adrenergic pathways proteins in myometrial of type II and gestational diabetics vs control patients with administration of vasopressors

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
96

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M5G1X5
        • Recruiting
        • Mount Sinai Hospital
        • Sub-Investigator:
          • Cynthia Maxwell, MD
        • Contact:
        • Sub-Investigator:
          • Caroline Carruthers
        • Sub-Investigator:
          • Joseph Park, BSc
        • Sub-Investigator:
          • Anuradha Baishnob, BSc

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Patients who have given consent to participate in the study
  • Patients with gestational age 37-41 weeks
  • Patients previously diagnosed with either Type II or Gestational diabetes. For the healthy control group, no previous diagnosis is required for inclusion
  • Patients of 19-45 years
  • Patients of normal BMI (18-30 BMI) for the healthy control group only
  • Baby is registered as normal weight for size for the healthy control group only
  • Non-laboring patients, not exposed to exogenous oxytocin
  • Patients requiring elective primary or first repeat caesarean delivery
  • Patients undergoing caesarean delivery under spinal anesthesia

Exclusion Criteria:

  • Patients who refuse to give written informed consent
  • Patients who require general anesthesia
  • Patients in labor and those receiving oxytocin for induction of labor
  • Emergency caesarean delivery in labor
  • Patients who have had previous uterine surgery involving myometrial dissection or >1 previous caesarean delivery
  • Patients with risk factors for PPH such as those with polyhydramnios, preeclampsia, multiple gestation, morbid obesity, macrosomia (large for size baby), and previous history of PPH. However, for diabetic group, those with morbid obesity and macrosomia will not be excluded as these conditions are almost always associated with diabetes.
  • For the healthy control group only, a BMI >30 or <18
  • Maternal age >45

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: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
No Intervention: Control
The myometrial samples are bathed in physiological salt solution (PSS) only.
Active Comparator: Ephedrine
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of ephedrine.
Drug: Ephedrine
Ephedrine in solution, at applicable concentrations based on literature.
Active Comparator: Phenylephrine
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of phenylephrine.
Drug: Phenylephrine
Phenylephrine, at applicable concentrations based on literature.
Active Comparator: Norepinephrine
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of norepinephrine.
Drug: Norepinephrine
Norepinephrine, at applicable concentrations based on literature.
Active Comparator: Control + oxytocin
The myometrial samples are bathed in physiological salt solution (PSS) and oxytocin.
Drug: Oxytocin
Oxytocin, at applicable concentrations based on literature.
Other Names:
  • pitocin
Active Comparator: Ephedrine + oxytocin
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of ephedrine and oxytocin..
Drug: Ephedrine
Ephedrine in solution, at applicable concentrations based on literature.
Drug: Oxytocin
Oxytocin, at applicable concentrations based on literature.
Other Names:
  • pitocin
Active Comparator: Phenylephrine + oxytocin
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of phenylephrine and oxytocin..
Drug: Phenylephrine
Phenylephrine, at applicable concentrations based on literature.
Drug: Oxytocin
Oxytocin, at applicable concentrations based on literature.
Other Names:
  • pitocin
Active Comparator: Norepinephrine + oxytocin
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of norepinephrine and oxytocin..
Drug: Norepinephrine
Norepinephrine, at applicable concentrations based on literature.
Drug: Oxytocin
Oxytocin, at applicable concentrations based on literature.
Other Names:
  • pitocin

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Motility index
Time Frame: 4 hours

Motility index (MI) is a calculated outcome, based on the formula: frequency/(10 x amplitude).

Frequency and amplitude are secondary outcome measures as described below.

The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
4 hours

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Integrated area under response curve (AUC)
Time Frame: 4 hours
4 hours
Amplitude of contraction
Time Frame: 4 hours
The maximum extent of uterine muscle contraction, measured in grams (g). The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
4 hours
Frequency of contraction
Time Frame: 4 hours
The number of contractions in uterine muscle (myometrium) over 10 minutes, spontaneously and in response to an agonist. The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
4 hours

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Mrinalini Balki, MD, Mount Sinai Hospital

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 18, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 22, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 22, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 29, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 6, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 31, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 24-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

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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