NCT04748874

Brief Summary

The purpose of this randomized controlled trial is to investigate if immediate single blastocyst transfer (in the first menstrual cycle following oocyte retrieval) is non-inferior to standard postponed single blastocyst transfer (in the second or subsequent menstrual cycle following oocyte retrieval) in modified natural cycle frozen-thawed embryo transfer (mNC-FET) in terms of live birth rate.

Trial Health

55
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Trial Health Score

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

Trial has exceeded expected completion date
Enrollment
464

participants targeted

Target at P75+ for not_applicable

Timeline
Completed

Started Apr 2021

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
active not recruiting

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

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

December 18, 2020

Completed
2 months until next milestone

First Posted

Study publicly available on registry

February 10, 2021

Completed
2 months until next milestone

Study Start

First participant enrolled

April 1, 2021

Completed
4.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 1, 2026

Completed
4 months until next milestone

Study Completion

Last participant's last visit for all outcomes

June 1, 2026

Completed
Last Updated

April 8, 2025

Status Verified

April 1, 2025

Enrollment Period

4.8 years

First QC Date

December 18, 2020

Last Update Submit

April 4, 2025

Conditions

InfertilityIVF

Keywords

Frozen embryo transferImmediate FETPostponed FETmNC FET

Outcome Measures

Primary Outcomes (2)

  • Live birth rate per randomized patient

    Live birth rate in patients randomized to immediate versus postponed FET

    One-year follow-up after a positive pregnancy test

  • Live birth rate per protocol

    Live birth rate in patients randomized to immediate versus postponed FET minus dropouts

    One-year follow-up after a positive pregnancy test

Secondary Outcomes (15)

  • Live birth rate per blastocyst transfer

    One-year follow-up after a positive pregnancy test

  • Positive hCG rate per randomized patient and per blastocyst transfer

    16 days after ovulation trigger (hCG+16)

  • Ongoing pregnancy rate per randomized patient and per blastocyst transfer

    Ultrasound at 7-8 weeks of gestation

  • Biochemical pregnancy loss

    16 days after ovulation trigger (hCG+16) and up to 7-8 weeks

  • Clinical pregnancy loss

    Routine ultrasound at 7-8 weeks of gestation or ad hoc ultrasound before 22 weeks of gestation

  • +10 more secondary outcomes

Study Arms (2)

Immediate mNC-FET

EXPERIMENTAL

In the immediate arm, patients undergo mNC-FET in the menstrual cycle immediately following oocyte retrieval and failed fresh embryo transfer or freeze-all.

Procedure: Immediate mNC-FET

Postponed mNC-FET

NO INTERVENTION

Standard procedure where mNC-FET is performed at least one full menstrual cycle after failed fresh embryo transfer or freeze-all cycle.

Interventions

Immediate mNC-FETPROCEDURE

In the immediate arm, patients undergo mNC-FET in the menstrual cycle immediately following oocyte retrieval and failed fresh embryo transfer or freeze-all.

Immediate mNC-FET

Eligibility Criteria

Age18 Years - 40 Years
Sexfemale
Healthy VolunteersNo
Age GroupsAdult (18-64)

You may qualify if:

  • Patients eligible for FET in a modified natural cycle
  • Regular menstrual cycle (23-35 days)
  • Vitrified day 5 or 6 blastocyst
  • Blastocyst Gardner score \> or = 3BB at the day of vitrification

You may not qualify if:

  • Uterine malformations or presence of hydrosalpinx
  • Submucosal uterine myomas
  • Uterine polyps
  • Allergy to standard fertility medication
  • Contradiction to standard fertility medication
  • Male of female HIV, hepatitis B or C
  • Preimplantation Genetic Testing (PGT) in the fresh cycle
  • Severe OHSS during the fresh cycle (defined as need for ascites drainage and/or hospital admission)
  • Oocyte donation
  • Testicular sperm aspiration (TESA)

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Fertility department, Rigshospitalet

Copenhagen, 2100, Denmark

Location

Related Publications (2)

  • Bergenheim S, Saupstad M, Colombo C, Moller JE, Bogstad JW, Freiesleben NC, Behrendt-Moller I, Praetorius L, Oxlund B, Nohr B, Husth M, Lokkegaard E, Sopa N, Pinborg A, Lossl K, Schmidt L. Psychosocial and physical wellbeing in women and male partners undergoing immediate versus postponed modified natural cycle frozen embryo transfer after ovarian stimulation and oocyte pick-up: a sub-study of a randomized controlled trial. Hum Reprod. 2025 Jan 1;40(1):96-109. doi: 10.1093/humrep/deae260.

    PMID: 39673443DERIVED

  • Bergenheim SJ, Saupstad M, Pistoljevic N, Lyng Forman J, Larsen EC, Bogstad JW, Fynbo M, Hashem N, Freiesleben NC, Nohr B, Andersen LF, Humaidan P, Ziebe S, Pinborg AB, Lossl K. Immediate versus postponed single blastocyst transfer in modified natural cycle frozen embryo transfer (mNC-FET): a study protocol for a multicentre randomised controlled trial. BMJ Open. 2021 Oct 27;11(10):e053234. doi: 10.1136/bmjopen-2021-053234.

    PMID: 34706963DERIVED

MeSH Terms

Conditions

Infertility

Condition Hierarchy (Ancestors)

Genital DiseasesUrogenital Diseases

Study Officials

  • Anja B Pinborg, Prof. DMSc

    Fertility department , Rigshospitalet

    STUDY DIRECTOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
MD, PhD

Study Record Dates

First Submitted

December 18, 2020

First Posted

February 10, 2021

Study Start

April 1, 2021

Primary Completion

February 1, 2026

Study Completion

June 1, 2026

Last Updated

April 8, 2025

Record last verified: 2025-04

Data Sharing

IPD Sharing
Will share

Data from the trial will be shared according to the ICJME guidelines. On request, data can be shared with parties presenting relevant aims for the use of data. Purposes and financial aspects of the other party must be approved by the steering committee of the "FET-immediate" research team. Data will not be shared with groups presenting research projects with the same aims or purposes as ours. No data will be shared until three months after publication of papers reporting the primary and secondary outcomes of the trial. Any new research project must be approved by Danish authorities. The requesting party will cover the costs for data sharing.

Shared Documents
STUDY PROTOCOL

Locations

DK(1)