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.
Quick facts
| Study type | Observational |
|---|---|
| Ages | 18 Years and up |
| Sex | Women only |
| Enrollment | 2400 (estimated) |
| Sponsor | Infertility Treatment Center Dortmund Academic / other |
| Locations | 1 site (Dortmund, North Rhine-Westphalia) |
| Status | Recruiting |
| Started | June 26, 2024 |
| Main results expected | January 2028 |
| Study ends | March 2028 |
| Registry record updated | October 1, 2026 |
| Trial ID | NCT06447077 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
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Infertility treatment center Dortmund
Dortmund, North Rhine-Westphalia, Germany Recruiting
Study contacts
- Principal investigator: Stefan Dieterle, MD — University of Witten/Herdecke
- Study coordinator: Stefan Dieterle, MD
- Email: dieterle@kinderwunschzentrum.org
- Phone: 00492315575450
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.