“Is It Over Even for Euploid Embryos After Three Failures?”… Tracking Up to Six Consecutive Transfers
- Tracking 5,811 women undergoing single PGT-A euploid embryo transfers: First-transfer live birth rate was 63.1%
- Estimated cumulative live birth probability reached 92.0% by the 3rd transfer, 98.3% by the 5th, and 98.8% by the 6th
- Per-transfer success rates did not sharply plummet after the second transfer… Warning against prematurely equating early failures with true implantation failure
- Researchers: “Findings support continuing sequential transfers of euploid embryos after initial failed cycles”
“PGT-A confirmed my embryo was chromosomally normal, but it has already failed to implant twice. Could there be an underlying uterine issue?”
This is an increasingly common concern across fertility forums. When an embryo confirmed to have a normal chromosome complement—a euploid embryo—fails to implant, patient anxiety often intensifies. Having eliminated embryonic chromosomal aneuploidy (the single largest contributor to IVF failure), patients naturally begin suspecting localized uterine pathology, immunological rejection, or thrombophilic clotting disorders.
If a euploid embryo fails to implant two or three times, should it automatically be labeled “recurrent implantation failure” (RIF)? And realistically, how many euploid transfers are needed before the cumulative likelihood of a live birth is maximized?
A large-scale study published in the journal Fertility and Sterility provides clear numbers to answer this question.
Conducted by researchers at the New York University (NYU) Grossman School of Medicine and NYU Langone Fertility Center, the study showed that when single PGT-A euploid embryos were transferred consecutively, the estimated cumulative probability of achieving at least one live birth rose from 63.1% after the first transfer to 92.0% after the third, 98.3% after the fifth, and 98.8% by the sixth transfer.
First Euploid Transfer Yields a 63.1% Live Birth Rate
The investigators analyzed 5,811 women who underwent IVF with preimplantation genetic testing for aneuploidy (PGT-A) followed by sequential single euploid embryo transfers between 2014 and 2024, encompassing a total of 7,763 euploid transfer cycles.
The findings revealed that the live birth rate (LBR) for the first euploid transfer was 63.1%. Viewed from the opposite perspective, even with an embryo verified to be chromosomally normal, more than a third of patients did not achieve a live birth on their initial attempt.
| Transfer Attempt | Per-Cycle Live Birth Rate (LBR) |
| 1st Transfer | 63.1% |
| 2nd Transfer | 54.0% |
| 3rd Transfer | 53.1% |
| 4th Transfer | 50.4% |
| 5th Transfer | 57.6% |
| 6th Transfer | 28.6%* |
(Note: The 6th transfer cohort included only 7 patients [95% CI: 8.2%–64.1%], making this single data point statistically inconclusive).
While success declined significantly from the first to the second transfer, per-cycle live birth rates showed no further statistically significant decline between the second and fifth transfers.
This is a pivotal clinical takeaway: experiencing one or two failed euploid transfers does not mean the developmental potential of subsequent euploid embryos progressively degrades toward zero.
Cumulative Live Birth Probability Reaches 92.0% by the Third Transfer
The study’s most reassuring findings lie in its cumulative outcomes.
Using Kaplan–Meier survival analysis to model the cumulative probability of achieving at least one live birth across sequential single euploid transfers:
- 1st Transfer: 63.1%
- 2nd Transfer: 83.0%
- 3rd Transfer: 92.0%
- 4th Transfer: 96.0%
- 5th Transfer: 98.3%
- 6th Transfer: 98.8%
For an individual who has failed three euploid transfers, those three failed cycles represent a 100% failure rate in their lived experience. However, from an epidemiological and population standpoint, patients who fail to achieve a live birth by the third euploid transfer narrow into a small statistical minority:
- Fewer than 5% of patients failed to achieve a live birth after 3 consecutive euploid transfers (meeting the classical statistical threshold for true recurrent implantation failure).
- Fewer than 2% failed to achieve a live birth after 5 consecutive euploid transfers.
Does “Three Failed Euploid Transfers = Uterine Pathology” Always Hold?
The central message of this study is not that “transferring euploid embryos will eventually work for everyone without exception.” Rather, it cautions against prematurely concluding that severe, irreversible implantation pathology exists after just one or two failed transfers.
A euploid embryo is not a guaranteed baby. Chromosomal normality confirms that the embryo possesses the correct number of chromosomes, but it cannot evaluate epigenetic programming, metabolic competence, mitochondrial capacity, or subtle sub-chromosomal microdeletions.
In this study:
- After the 1st transfer: Complete implantation failure occurred in 20.0%, biochemical pregnancy loss in 8.4%, and clinical miscarriage in 7.1%.
- After the 2nd transfer: Rates were 23.8%, 11.0%, and 9.8%, respectively.
These adverse pregnancy outcome rates did not show a compounding, progressive spike across subsequent transfer cycles.
This aligns with the 2026 American Society for Reproductive Medicine (ASRM) Committee Opinion on recurrent implantation failure, which stresses evaluating anatomical, endocrine, and lifestyle factors in patients facing repeated transfer failures while avoiding the temptation to categorize every patient with repeated failures into an identical diagnostic box.
Why 98.8% Should Not Be Taken as an Absolute Personal Guarantee
Patients must be careful not to interpret the 98.8% cumulative figure as an unconditional personal certainty.
This was a retrospective cohort analysis, not a prospective randomized controlled trial. A substantial portion of patients who did not achieve a live birth in earlier cycles discontinued treatment rather than proceeding to subsequent transfers:
- Of the total 5,811 women, 4,709 achieved a live birth (81.0%).
- Of the 1,102 women who did not achieve a live birth, 1,097 discontinued treatment before completing six transfers.
- Only 5 patients completed all six euploid transfers without achieving a live birth.
When the investigators applied an ultra-conservative assumption—presuming that 100% of patients who dropped out would have failed every subsequent transfer—the conservative cumulative live birth rate remained 81.0%, compared to the Kaplan–Meier estimate of 98.8%. The true clinical probability falls between these two figures.
Furthermore, the study excluded patients with uncorrected intra-cavitary uterine pathology, major congenital uterine malformations, donor oocyte cycles, and gestational surrogacy. Consequently, these high cumulative success figures cannot be directly generalized to patients with untreated diffuse adenomyosis, active intracavitary fibroids, or unclipped hydrosalpinges.
Looking Beyond the Number of Failures: “Why Did It Fail?”
Despite these methodological caveats, the clinical implications for fertility patients remain profound.
Failing a first euploid transfer does not compromise the intrinsic potential of the next euploid embryo in line. Even after a second or third unsuccessful attempt, the per-transfer statistical probability of success does not experience an exponential collapse.
These results mirror a large-scale multicenter study published in Human Reproduction (2024), which reported sustained live birth rates through fourth and fifth sequential euploid transfers, yielding an overall cumulative live birth rate of 98.1% in a selected cohort without uncorrected uterine pathology.
These findings reshape how we view euploid transfer failure.
Rather than stopping at “why did three euploid embryos fail?”, clinicians and patients should evaluate whether the failures have crossed into a statistically rare tier, whether targeted diagnostic evaluations of the uterine cavity, fallopian tubes, or endometrium are warranted, and whether solid clinical evidence supports continuing sequential transfers with the remaining euploid embryos.
The label “euploid” carries immense weight, but it does not denote an embryo that is guaranteed to implant. This study demonstrates that the true nature of euploid embryo transfer is not defined by absolute single-cycle certainty, but by the fact that one or two early failures do not justify writing off the remaining potential as an impossibility.
Medical Source & Study Reference
- Journal: Fertility and Sterility (Published online July 2026).
- Study Title: Cumulative probability of a live birth after up to six sequential single euploid embryo transfers
- Lead Institutions: New York University (NYU) Grossman School of Medicine; NYU Langone Fertility Center, New York, NY, USA.
- Cohort Size: 5,811 women undergoing 7,763 single euploid frozen embryo transfers (2014–2024).
- Article Identifiers: Article ID: S0015-0282(26)00572-8 | DOI: 10.1016/j.fertnstert.2026.07.016 | PMID: 42508682
※ This article provides general scientific and medical information and does not replace individualized clinical diagnosis or care. Diagnostic determinations regarding euploid transfer failure and recurrent implantation failure must be made collaboratively with an attending reproductive endocrinologist, taking into account embryonic quality, uterine cavity and endometrial health, tubal patency, maternal age, underlying comorbidities, and obstetric history. Repeated failures alone should not justify unproven or invasive add-on therapies without thorough clinical evaluation.
※ The images associated with this article were generated using generative AI (ChatGPT, OpenAI) as illustrative visual references and do not depict real individuals.
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