Frozen Embryo TransferNCT06526520
Relaxin Measurement in Different Endometrial Preparation Approaches for Frozen Embryo Transfer
An observational study of Frozen Embryo Transfer, run by ART Fertility Clinics LLC at 1 site in United Arab Emirates.
Trial summary
To investigate the levels of Relaxin in different types of endometrial preparation for a frozen embryo transfer cycle. Up to now it is unclear, whether ovulation with a functional corpus luteum (CL) will be present in a natural proliferative phase (NPP) endometrial preparation approach. Read more about this study
- Who is it for?
- Ages 18 to 35 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Frozen Embryo Transfer
- What is being tested?
- Exposure to progesterone or HRT medication
- How many people
- 5 participants
- Where
- 1 siteUnited Arab Emirates
- Study dates
- 1 Aug 2024to 31 Dec 2026
- 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 35 years
- Women only
- Healthy volunteers accepted
- Adult
Study population: - healthy volunteers with regular cycles
Who may be able to join
- regular menstrual cycles
Who cannot join
- abnormal findings of the ovaries (e.g endometriosis)
- Intake of any hormones within 3 months of study start
- desire to become pregnant
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Arab Emirates1 site, 1 recruiting
- Recruiting
ART Fertiltiy Clinic
Abu Dhabi, Abu Dhabi Emirate, 60202
Barbara Lawrenz, 00971526500757, barbara.lawrenz@artfertilityclinics.com
Jonalyn Edades, MBA, barbara.lawrenz@web.de
About this study
To investigate the levels of Relaxin in different types of endometrial preparation for a frozen embryo transfer cycle. Up to now it is unclear, whether ovulation with a functional corpus luteum (CL) will be present in a natural proliferative phase (NPP) endometrial preparation approach.
Read the detailed description
The last years have seen a distinct shift from fresh (fresh ET) to frozen embryo transfer (FET) cycles. Furthermore it became obvious, that the endometrial preparation approach has a significant impact on the course of the pregnancy and that a HRT endometrial preparation approach is associated with a higher risk for bleeding and miscarriages in early pregnancy and for the development of pregnancy induced hypertension and pre-eclampsia later in pregnancy.
These conditions are attributed to the absence of a CL in the HRT approach. Lately a new endometrial preparation approach is discussed and performed, the so called natural proliferative phase protocol, in which the follicle growth is monitored and when the lining is deemed to have a sufficient thickness and the triple lining pattern, exogeneous progesterone is started to induce secretory transformation before spontaneous ovulation. Despite some studies showing, that exogeneous progesterone administration might induce ovulation, it is not clear whether there will be a CL, producing Relaxin, in the NPP approach.
- Conditions
- Frozen Embryo Transfer
- Being tested
- Exposure to progesterone or HRT medication
- Keywords
- frozen embryo transfer, hormonal replacement cycle, natural cycle, Relaxin
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Exposure to progesterone or HRT medicationDrug
to add either progesterone only in the NPP protocol or E2 and progesterone in a HRT protocol
| Study group | Role | What they receive |
|---|---|---|
| Natural cycle | Monitoring of a natural cycle | |
| natural proliferative phase cycle | Monitoring of a natural proliferative phase cycle Receives: Drug: Exposure to progesterone or HRT medication | |
| Hormonal replacement cycle | Monitoring of a hormonal replacement cycle Receives: Drug: Exposure to progesterone or HRT medication |
What is being measured
The primary outcome is the main question the study is designed to answer.
Relaxin measurement
Measurement of Relaxin in the different types of frozen embryo transfer
Measured: 4 to 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Jul 2024
- Study start1 Aug 2024
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Frozen Embryo TransferStudies of the same condition, open and under way.
- 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
- Case crossover
- Time perspective
- Prospective
- Enrolment
- 5 participants (estimated)
Sponsor and investigators
- Lead sponsor
- ART Fertility Clinics LLC
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Barbara Lawrenz, PhD, Principal investigator, ART Fertility Clinic
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06526520
- Sponsor's protocol ID
- 2406-ABU-007-BL
- Status last verified
- May 2026
- First submitted
- 25 Jul 2024
- Last updated
- 11 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: on request
Study at a glance
From the registry record, last updated by the sponsor on 11 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Relaxin Measurement in Different Endometrial Preparation Approaches for Frozen Embryo Transfer
- ClinicalTrials.gov ID
- NCT06526520
- Acronym / sponsor ID
- 2406-ABU-007-BL
- Conditions
- Frozen Embryo Transfer
- Keywords
- frozen embryo transfer, hormonal replacement cycle, natural cycle, Relaxin
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 5 participants (estimated)
- Lead sponsor
- ART Fertility Clinics LLCUniversity, hospital or other
- Study start
- 1 Aug 2024 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 29 Jul 2024 (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.
To investigate the levels of Relaxin in different types of endometrial preparation for a frozen embryo transfer cycle. Up to now it is unclear, whether ovulation with a functional corpus luteum (CL) will be present in a natural proliferative phase (NPP) endometrial preparation approach.
Detailed description
The last years have seen a distinct shift from fresh (fresh ET) to frozen embryo transfer (FET) cycles. Furthermore it became obvious, that the endometrial preparation approach has a significant impact on the course of the pregnancy and that a HRT endometrial preparation approach is associated with a higher risk for bleeding and miscarriages in early pregnancy and for the development of pregnancy induced hypertension and pre-eclampsia later in pregnancy.
These conditions are attributed to the absence of a CL in the HRT approach. Lately a new endometrial preparation approach is discussed and performed, the so called natural proliferative phase protocol, in which the follicle growth is monitored and when the lining is deemed to have a sufficient thickness and the triple lining pattern, exogeneous progesterone is started to induce secretory transformation before spontaneous ovulation. Despite some studies showing, that exogeneous progesterone administration might induce ovulation, it is not clear whether there will be a CL, producing Relaxin, in the NPP approach.
Study design
- Observational model
- Case crossover
- Time perspective
- Prospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Natural cycle | – | –Monitoring of a natural cycle |
| natural proliferative phase cycle | – | Drug: Exposure to progesterone or HRT medicationMonitoring of a natural proliferative phase cycle |
| Hormonal replacement cycle | – | Drug: Exposure to progesterone or HRT medicationMonitoring of a hormonal replacement cycle |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- - healthy volunteers with regular cycles
Key inclusion criteria (1 listed)
- regular menstrual cycles
Key exclusion criteria (3 listed)
- abnormal findings of the ovaries (e.g endometriosis)
- Intake of any hormones within 3 months of study start
- desire to become pregnant
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 |
|---|---|---|
| Exposure to progesterone or HRT medicationto add either progesterone only in the NPP protocol or E2 and progesterone in a HRT protocol | Drug | Hormonal replacement cycle, natural proliferative phase cycle |
Primary outcome
Relaxin measurement
Time frame: 4 to 6 months
Measurement of Relaxin in the different types of frozen embryo transfer
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 11 May 2026.
- Individual participant dataSharing planned: No. on request
Related trials for Frozen Embryo Transfer
Not yet recruiting
Cryopreserved Pre-embryo Transfer in a Cytokine-rich Medium Versus Hyaluronic Acid
Frozen Embryo Transfer (FET)
Active, not recruitingPhase 3
Human Menopausal Gonadotropin Research in Infertility Assessing Cumulative Live Birth With Frozen Embryo Transfer.
Infertility (IVF Patients)
RecruitingPhase 2
Effect of FB301 on Vaginal Bacterial Profile in Women With Asymptomatic Vaginal Dysbiosis Undergoing a Mock Frozen Embryo Transfer Cycle
Vaginal Dysbiosis
Not yet recruitingObservational study
Association Between Serum Progesterone Levels on Embryo Transfer Day and Clinical Pregnancy in Frozen-thawed Embryo Transfer Cycles Using Hormone Replacement Therapy
Infertility Assisted Reproductive Technology
Recruiting
FET-LET-2x2: Clinical Pregnancy Rates After Frozen Embryo Transfer in Natural and Modified Natural Cycles
Infertility Female, Frozen Embryo Transfer (FET)
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.
Barbara Lawrenz, PhD principal investigator
ART Fertility Clinic
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 Frozen Embryo Transfer, run by ART Fertility Clinics LLC at 1 site in United Arab Emirates.
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 1 inclusion and 3 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: looking for participants now, as of the sponsor's last update on 11 May 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 United Arab Emirates. 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 Barbara Lawrenz, M.D. PhD (800 337845489, barbara.lawrenz@artfertilityclinics.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Relaxin measurement (time frame: 4 to 6 months). 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 11 May 2026.