InfertilityTEC-RELAXNCT07477340
Plasma Relaxin Measurement Based on Endometrial Preparation for Embryo Transfer
An observational study of Infertility and Embryos Transfert, run by Hospices Civils de Lyon at 1 site in France.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Infertility, Embryos Transfert
- What is being tested?
- Relaxine dosage
- How many people
- 60 participants
- Where
- 1 siteFrance
- Study dates
- 1 May 2026to 1 Feb 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Women only
- Adult
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.
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site
Service de Médecine et de la Reproduction HFME
Bron, Rhone, 69500
FRAISON Eloise, Dr, 04 72 12 94 12 ext. +33, Eloise.fraison@chu-lyon.fr
FRAISON Eloise, Dr
About this study
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.
Read more
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.
- Conditions
- Infertility, Embryos Transfert
- Being tested
- Relaxine dosage
- Keywords
- Relaxine level, Embryos transfert, Pregnancy
- Medical subject headings
- Infertility
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Relaxine dosageBiological
An additionnal 5m blood sample will be taken during the current blood sample at the beginning of the pregnancy.
| Study group | Role | What they receive |
|---|---|---|
| Fresh ambryo transfert | Not described Receives: Biological: Relaxine dosage | |
| Frozen embryo transfert with Follicle stimulating hormone | Not described Receives: Biological: Relaxine dosage | |
| Frozen embryo transfert with hormonal substitutive treatment cycle | Not described Receives: Biological: Relaxine dosage |
What is being measured
The primary outcome is the main question the study is designed to answer.
Relaxin Level
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.
Measured: Up to 19 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Mar 2026
- Study start1 May 2026 (estimated)
- Primary completion1 Feb 2028 (estimated)
- Study completion1 Feb 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for InfertilityStudies of the same condition, open and under way.
- More trials run by Hospices Civils de LyonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospices Civils de Lyon
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07477340
- Sponsor's protocol ID
- 69HCL26_0142
- Acronym
- TEC-RELAX
- Status last verified
- Mar 2026
- First submitted
- 3 Mar 2026
- Last updated
- 17 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Plasma Relaxin Measurement Based on Endometrial Preparation for Embryo Transfer
- ClinicalTrials.gov ID
- NCT07477340
- Acronym / sponsor ID
- TEC-RELAX / 69HCL26_0142
- Conditions
- Infertility, Embryos Transfert
- Keywords
- Relaxine level, Embryos transfert, Pregnancy
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Hospices Civils de LyonUniversity, hospital or other
- Study start
- 1 May 2026 (estimated)
- Primary completion
- 1 Feb 2028 (estimated)
- Study completion
- 1 Feb 2028 (estimated)
- First posted
- 17 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Fresh ambryo transfert | – | Biological: Relaxine dosage |
| Frozen embryo transfert with Follicle stimulating hormone | – | Biological: Relaxine dosage |
| Frozen embryo transfert with hormonal substitutive treatment cycle | – | Biological: Relaxine dosage |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Age groups
- Adult
- 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.
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (6 listed)
- Uterine pathologies (adenomyosis, fibroids)
- Multiple pregnancies
- Spontaneous pregnancy
- Pregnancy through gamete donation
- Refusal to undergo obstetric ultrasounds
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Relaxine dosageAn additionnal 5m blood sample will be taken during the current blood sample at the beginning of the pregnancy. | Biological | Fresh ambryo transfert, Frozen embryo transfert with Follicle stimulating hormone, Frozen embryo transfert with hormonal substitutive treatment cycle |
Primary outcome
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.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Mar 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Infertility and Embryos Transfert, run by Hospices Civils de Lyon at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 17 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact FRAISON Eloise, Dr (04 72 12 94 12 ext. +33, Eloise.fraison@chu-lyon.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Relaxin Level (time frame: Up to 19 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Mar 2026.