Effect of Magnesium Sulphate Pre-exposure on Oxytocin-induced Contractility in Desensitized Human Myometrium

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

26 participants

Study Classification

INTERVENTIONAL

Study Start Date

2016-01-31

Study Completion Date

2017-04-30

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Postpartum hemorrhage (PPH) is the loss of more than 500ml of blood within 24 hours after delivery. It is a major cause of maternal morbidity and mortality across the globe.

Oxytocin is a naturally-occurring hormone that causes the uterus to contract, thereby causing labor. A synthetic form of oxytocin is used in obstetric medicine in the same way. It causes the uterus to contract by acting at the oxytocin receptor (OTR). It is used for both the prevention and the treatment of PPH. By causing the uterus to contract, it constricts the blood vessels within it, thus reducing bleeding.

Oxytocin is also used to augment labor in women with slow labor progression. Desensitization of the OTR after prolonged exposure to oxytocin occurs, leading to reduced contractions of the uterus with the same doses of oxytocin. This has been demonstrated in previous studies done by the investigators. The resultant need for a higher oxytocin dose to cause adequate uterine contraction has also been demonstrated in laboring women having received oxytocin for labor augmentation.

Magnesium sulphate (MgSO4) is widely used within obstetric medicine. It is used for seizure prevention and treatment in preeclampsia and eclampsia, and is used for fetal neuroprotection in preterm labor, to reduce the risk of cerebral palsy. It is well-known to have a relaxant effect on uterine muscle, and as such, has been used as a tocolytic agent in preterm labour to prevent premature contractions and premature delivery. The effect of MgSO4 on contractions in oxytocin pre-treated myometrium has not been fully elucidated with human lab studies. There are suggestions it may lead to increased oxytocin requirements or increased postpartum hemorrhage (PPH) in preeclamptic patients. This bears significance in the preeclamptic and eclamptic populations who are likely to be receiving MgSO4 in combination with oxytocin.

The investigators hypothesize that MgSO4 will reduce uterine contractions in oxytocin pre-treated myometrium, as well as untreated myometrium, and higher oxytocin doses will be needed to produce equivalent contractions. This will help us to better understand the implications of the use of these drugs together in the clinical setting.

Related Clinical Trials

Explore similar clinical trials based on study characteristics and research focus.

Recovery of Oxytocin Responsiveness in Pregnant Human Myometrial Explants After Oxytocin-Induced Desensitization: an In-vitro Analysis of Oxytocin Receptor Expression and Signaling

NCT02762669

Postpartum Hemorrhage

TERMINATED NA

Investigating the Effect of Extracellular Calcium on Oxytocin-induced Human Myometrial Contractility In-vitro

NCT02274454

Postpartum Hemorrhage

COMPLETED NA

Investigating the Effect of Pulsatile Administration of Oxytocin on the Desensitization of Human Myometrium In-vitro

NCT02338089

Postpartum Hemorrhage

COMPLETED NA

Recovery of Oxytocin Responsiveness in Pregnant Human Myometrial Explants After Oxytocin-Induced Desensitization

NCT02051231

Postpartum Hemorrhage

COMPLETED NA

In Vitro Evaluation of Spontaneous and Oxytocin-induced Contractility of Pregnant Human Myometrium During Exposure to Dexmedetomidine

NCT05511415

Postpartum Hemorrhage

COMPLETED NA

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

MgSO4 is known to cause relaxation of uterine muscle in the doses used for preeclampsia and eclampsia and fetal neuroprotection. In these clinical settings, after delivery, oxytocin is often given to prevent or treat PPH. There is evidence that patients with preeclampsia already have a higher risk of PPH than non-preeclamptic patients. In the presence of the effects of MgSO4 treatment on the uterus, PPH could be worse in theory. If patients have had oxytocin-augmented labor, then the desensitization effect on the uterus also comes into play. Performing this study in vitro will allow us to assess the effects on the uterine muscle of MgSO4 in oxytocin-desensitized tissue samples.

Scientific evidence on pregnancy outcomes in these patients is timely and important. A study of myometrial contractility under controlled conditions is likely to provide us with information on the interactions between oxytocin and MgSO4 that occurs in many clinical scenarios, eliminating any confounders that could be encountered in clinical settings. The investigators hope to determine the myometrial contraction patterns induced by oxytocin in the presence of MgSO4, including in myometrial specimens pre-treated with oxytocin plus MgSO4, to mimic the clinical scenarios in preeclampsia and fetal neuroprotection. This will expand the depth of our understanding of the desensitization phenomenon, and could provide valuable insight into the mechanism responsible for PPH in these patient populations. This study will form a basis for future modifications in oxytocin augmentation regimens and pharmacotherapy for control of uterine atony and PPH in these patient populations being simultaneously treated with MgSO4.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Postpartum Hemorrhage

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Control (no oxytocin) pretreatment

The myometrial samples are bathed in physiological saline solution (PSS).

Group Type NO_INTERVENTION

No interventions assigned to this group

Magnesium Sulphate

The myometrial samples are bathed in a 3.5mM magnesium sulphate solution.

Group Type ACTIVE_COMPARATOR

Magnesium Sulphate

Intervention Type DRUG

Magnesium sulphate, 3.5mM solution

Magnesium Sulphate + oxytocin

The myometrial samples are bathed in a 3.5mM magnesium sulphate plus 10-5M oxytocin solution.

Group Type ACTIVE_COMPARATOR

Oxytocin

Intervention Type DRUG

Oxytocin, 10-5M solution

Magnesium Sulphate

Intervention Type DRUG

Magnesium sulphate, 3.5mM solution

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Oxytocin

Oxytocin, 10-5M solution

Intervention Type DRUG

Magnesium Sulphate

Magnesium sulphate, 3.5mM solution

Intervention Type DRUG

Other Intervention Names

Discover alternative or legacy names that may be used to describe the listed interventions across different sources.

pitocin

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Patients who give written consent to participate in this study
* Patients with gestational age 37-41 weeks
* Non-laboring patients, not exposed to exogenous oxytocin
* Patients requiring primary Cesarean delivery or first repeat Cesarean delivery under spinal anesthesia

Exclusion Criteria

* Patients who refuse to give written informed consent
* Patients who require general anesthesia
* Patients who had previous uterine surgery or more than one previous Cesarean delivery
* Patients with any condition predisposing to uterine atony and postpartum hemorrhage, such as abnormal placentation, multiple gestation, preeclampsia, macrosomia, polyhydramnios, uterine fibroids, bleeding diathesis, chorioamnionitis, or a previous history of postpartum bleeding
* Emergency Cesarean section in labor
* Patients with medical/pregnancy related conditions, such as diabetes, preeclampsia and essential hypertension

Minimum Eligible Age

16 Years

Maximum Eligible Age

40 Years

Eligible Sex

FEMALE

Accepts Healthy Volunteers

Yes