Plasma Relaxin Measurement Based on Endometrial Preparation for Embryo Transfer (TEC-RELAX)

March 13, 2026 updated by: Hospices Civils de Lyon

Pregnancies achieved through assisted reproductive technology (ART) are associated with more obstetric complications than natural pregnancies.

In pregnancies achieved through in vitro fertilization, different obstetric outcomes are observed depending on the type of embryo transfer performed and the type of endometrial preparation. Studies comparing obstetric complications according to the type of transfer performed (fresh or frozen embryo transfer) suggest an increased risk of preeclampsia, fetal macrosomia, and postpartum hemorrhage in pregnancies achieved through frozen embryo transfer.

Depending on the endometrial preparation methods used prior to frozen embryo transfer, different obstetric risks are observed. Comparisons mainly focus on stimulated cycles versus natural cycles and spontaneous pregnancies. Pregnancies achieved through frozen embryo transfer in a stimulated cycle are thought to be at greater risk of preeclampsia, fetal macrosomia, and postpartum hemorrhage than natural cycles and spontaneous pregnancies. One of the first markers of this vascular adaptation is the cranio-caudal length (CCL).

Indeed, the cranio-caudal length of embryos in the first trimester is a good reflection of embryonic growth and therefore of vascular adaptation in the first trimester of pregnancy. Differences in growth between embryos from fresh transfers, frozen transfers, and spontaneous pregnancies are visible early on, as early as the first trimester.

The hypotheses put forward to explain these differences include the secretion of relaxin by the corpus luteum, which is present in the natural cycle but not in the substituted cycle. This hormone plays a role in cardiovascular and renal adaptation to pregnancy in the first trimester. Low levels of relaxin would therefore be associated with poorer cardiorenal adaptation in the first trimester and thus with greater vascular risks in late pregnancy.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet 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.

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.
Observational

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.
60

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

  • France
    • Rhone
      • Bron, Rhone, France, 69500
        • Service de Médecine et de la Reproduction HFME
        • Contact:
        • Principal Investigator:
          • FRAISON Eloise, Dr

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

N/A

Sampling Method

Non-Probability Sample

Study Population

This study will focus on patients who underwent fresh or frozen embryo transfer in the Reproductive Medicine Department and were monitored at the Women's and Children's Hospital, resulting in a progressive pregnancy with first trimester ultrasound.

Description

Inclusion Criteria:

  • Primiparous women
  • Intra-couple ART
  • Of childbearing age undergoing assisted reproductive technology (18 to 44 years and 11 months)
  • Who underwent a fresh or frozen embryo transfer during the inclusion period resulting in a progressing monofetal pregnancy (ultrasound showing an embryo with cardiac activity).
  • Able to understand the ins and outs of the study
  • Having indicated their willingness to participate in the study

Exclusion Criteria:

  • Uterine pathologies (adenomyosis, fibroids)
  • Multiple pregnancies
  • Spontaneous pregnancy
  • Pregnancy through gamete donation
  • Refusal to undergo obstetric ultrasounds
  • Subject participating in interventional research involving an exclusion period still ongoing at the time of pre-inclusion

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

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
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.
Fresh ambryo transfert
Biological: Relaxine dosage
An additionnal 5m blood sample will be taken during the current blood sample at the beginning of the pregnancy.
Frozen embryo transfert with Follicle stimulating hormone
Biological: Relaxine dosage
An additionnal 5m blood sample will be taken during the current blood sample at the beginning of the pregnancy.
Frozen embryo transfert with hormonal substitutive treatment cycle
Biological: Relaxine dosage
An additionnal 5m blood sample will be taken during the current blood sample at the beginning of the pregnancy.

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
Relaxin Level
Time Frame: Up to 19 weeks
Determine whether there is a difference in plasmatic relaxin levels in ng/ml depending on the type of transfer-fresh transfer versus TEC THS versus TEC FSH.
Up to 19 weeks

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.
Hospices Civils de Lyon

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 (Estimated)

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.
May 1, 2026

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.
February 1, 2028

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.
February 1, 2028

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).
March 3, 2026

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.
March 13, 2026

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.
March 17, 2026

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.
March 17, 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 13, 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.
March 1, 2026

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.
  • 69HCL26_0142

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

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.

Clinical Trials on Infertility

Clinical Trials on Relaxine dosage

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings