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Plasma Relaxin Measurement Based on Endometrial Preparation for Embryo Transfer

Plasma Relaxin Measurement Based on Endometrial Preparation for Embryo Transfer

Status
Not yet recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT07477340
Acronym
TEC-RELAX
Enrollment
60
Registered
2026-03-17
Start date
2026-05-01
Completion date
2028-02-01
Last updated
2026-03-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Embryos Transfert, Infertility

Keywords

Relaxine level, Embryos transfert, Pregnancy

Brief 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 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.

Interventions

BIOLOGICALRelaxine dosage

An additionnal 5m blood sample will be taken during the current blood sample at the beginning of the pregnancy.

Sponsors

Hospices Civils de Lyon
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 45 Years

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

Design outcomes

Primary

MeasureTime frameDescription
Relaxin LevelUp to 19 weeksDetermine 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.

Countries

France

Contacts

CONTACTFRAISON Eloise, Dr
Eloise.fraison@chu-lyon.fr04 72 12 94 12

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 18, 2026