Clinical trial Recruiting at 1 site Observational Ages 18 and up Women only

Comparing Day 5 and Day 6 Embryo Transfers for Pregnancy Rates

Official title: Impact of a Predetermined Day 5 Embryo Transfer Versus a Predetermined Day 6 Embryo Transfer on the Clinical Pregnancy Rate After Intracytoplasmic Sperm Injection (ICSI) Treatment

Run by Infertility Treatment Center Dortmund · NCT06447077 · Data updated 2026-11-12

This study is testing whether transferring embryos on day 5 or day 6 after treatment can lead to higher pregnancy rates for people undergoing fertility treatment.

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Quick facts

Study typeObservational
Ages18 Years and up
SexWomen only
Enrollment2400 (estimated)
SponsorInfertility Treatment Center Dortmund
Academic / other
Locations1 site (Dortmund, North Rhine-Westphalia)
StatusRecruiting
StartedJune 26, 2024
Main results expectedJanuary 2028
Study endsMarch 2028
Registry record updatedOctober 1, 2026
Trial IDNCT06447077 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates are women aged 18 and older undergoing their first ICSI cycle with a single embryo transfer.

Probably not a fit

Patients who are not undergoing ICSI treatment or those requiring multiple embryo transfers may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This prospective multicenter study aims to compare the clinical pregnancy rates of predetermined embryo transfers on day 5 versus day 6 after ICSI treatment. The study will involve patients undergoing single embryo transfers at three fertility centers in Germany. The primary endpoint is the detection of a gestational sac per embryo transfer, while the secondary endpoint focuses on the abortion rate per clinical pregnancy. This research seeks to determine if a day 6 transfer could provide advantages in embryo development assessment.

Why it matters

Potential benefit: If successful, this study could optimize embryo transfer timing, potentially increasing pregnancy rates for patients undergoing ICSI treatment.

How similar studies have gone: While previous studies have compared day 4 and day 5 transfers, this is the first prospective study examining the equivalence of day 5 versus day 6 transfers.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion criteria:

The patients to be included should be ≥18 years old. There is no upper age limit. Only ICSI treatments with a single embryo transfer (SET) should be included. Only the first cycle per patient should be evaluated.

Exclusion criteria:

none

Where it's running

  • Infertility treatment center Dortmund
    Dortmund, North Rhine-Westphalia, Germany
    Recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.