NCT07477340

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.

Trial Health

63
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
60

participants targeted

Target at P25-P50 for all trials

Timeline
18mo left

Started May 2026

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress15%
May 2026Feb 2028

First Submitted

Initial submission to the registry

March 3, 2026

Completed
14 days until next milestone

First Posted

Study publicly available on registry

March 17, 2026

Completed
2 months until next milestone

Study Start

First participant enrolled

May 1, 2026

Completed
1.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 1, 2028

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

February 1, 2028

Last Updated

March 17, 2026

Status Verified

March 1, 2026

Enrollment Period

1.8 years

First QC Date

March 3, 2026

Last Update Submit

March 13, 2026

Conditions

InfertilityEmbryos Transfert

Keywords

Relaxine levelEmbryos transfertPregnancy

Outcome Measures

Primary Outcomes (1)

  • 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.

    Up to 19 weeks

Study Arms (3)

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

Interventions

Relaxine dosageBIOLOGICAL

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

Fresh ambryo transfertFrozen embryo transfert with Follicle stimulating hormoneFrozen embryo transfert with hormonal substitutive treatment cycle

Eligibility Criteria

Age18 Years - 45 Years
Sexfemale
Age GroupsAdult (18-64)
Sampling MethodNon-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.

You may qualify if:

  • Primiparous women
  • Intra-couple ART
  • Of childbearing age undergoing assisted reproductive technology (18 to 44 years and 11 months)
  • Able to understand the ins and outs of the study
  • Having indicated their willingness to participate in the study

You may not qualify if:

  • Uterine pathologies (adenomyosis, fibroids)
  • Multiple pregnancies
  • Spontaneous pregnancy
  • Pregnancy through gamete donation
  • Refusal to undergo obstetric ultrasounds

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Service de Médecine et de la Reproduction HFME

Bron, Rhone, 69500, France

Location

MeSH Terms

Conditions

Infertility

Condition Hierarchy (Ancestors)

Genital DiseasesUrogenital Diseases

Central Study Contacts

FRAISON Eloise, Dr

CONTACT

04 72 12 94 12Eloise.fraison@chu-lyon.fr

Study Design

Study Type
observational
Observational Model
COHORT
Time Perspective
PROSPECTIVE
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

March 3, 2026

First Posted

March 17, 2026

Study Start

May 1, 2026

Primary Completion (Estimated)

February 1, 2028

Study Completion (Estimated)

February 1, 2028

Last Updated

March 17, 2026

Record last verified: 2026-03

Data Sharing

IPD Sharing
Will not share

Locations

FR(1)