Recruiting
Phase 3

Blastocyst vs. 8-Cell

Sponsor:

Beth Israel Deaconess Medical Center

Code:

NCT06746129

Conditions

Infertility (IVF Patients)

Eligibility Criteria

Sex: Female

Age: 18 - 44

Healthy Volunteers: Not accepted

Interventions

embryo transfer

Study Details

Brief summary:

Infertility affects more than 6 million women the United States and is a major life event that results in a wide range of socio-cultural, emotional, physical and financial problems. The most successful treatment for infertility, in-vitro fertilization (IVF), fertilizes a woman's eggs with her partner's sperm in a culture dish and transfers the resulting embryos into the uterus. Most of the time, prior to being transferred, embryos are grown in the dish for 5-7 days after which some of them reach an advanced stage (blastocyst stage). This has several advantages such as a lower chance of a multiple pregnancies (twins, triplets etc.) after transfer and fewer transfer procedures. However, it is possible that embryos would survive better if transferred into the uterus at the 8-cell stage after growing them for only 3 days. Thus, when patients only have a small number of embryos they and their physicians face the difficult choice when to transfer because there are currently no studies available to guide this decision.

This randomized controlled trial is comparing pregnancy outcomes and patient satisfaction of poor prognosis patients with 5 or fewer embryos undergoing either transfer of an advanced (blastocyst) or an 8-cell embryo.

This study will provide the data for the development of guidelines for IVF providers to make evidence-based decisions when to transfer embryos in poor prognosis IVF patients, reduce patients' anxiety regarding cycle cancellation and improve patient counseling, which will increase patients' ability to participate in the development of their treatment plan.

Conditions

Infertility (IVF Patients)

Study ID

NCT06746129

Start date

Sep 10, 2025

Status verified date

Mar, 2026

Completion date

Jun 30, 2031

Anticipated

Primary completion date

Dec, 2030

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18 - 44

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • autologous IVF cycle
  • ≤5 zygotes on day 1 of development
  • Fresh embryo transfer

Exclusion Criteria:

  • Planned preimplantation genetic testing (PGT) of all embryos
  • More than 2 previous IVF cycles
  • History of recurrent pregnancy loss (≥3)
  • Body mass index >40
  • Presence of uterine factor infertility
  • Planned gestational carrier
  • Endometrial lining <6mm measured on the day of trigger
  • Lupron-only trigger, elevated progesterone in the fresh cycle (≥1.5ng/ml)
  • Delayed fertilization (>18 hours)
  • Rescue intracytoplasmic sperm injection (following failed regular fertilization)
  • Use of non-ejaculated sperm (testicular sperm extraction)
  • Embryo transfer number outside American Society of Reproductive Medicine (ASRM) guidelines
  • Cycle is converted to a cycle in which all embryos are frozen

Study Design

Enrollment

1126 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: cleavage-stage embryo transfer

embryo(s) will be transferred on day 3 of embryo development (cleavage-stage embryo)

active comparator: blastocyst embryo transfer

embryo(s) will be transferred on day 5-7 of embryo development (blastocyst-stage embryo)

Interventions

embryo transfer

transfer of embryo(s) into the uterine cavity

Primary outcome measure

  • cumulative live birth per IVF cycle [ Time Frame: month 9 after embryo transfer ]

Central Contacts and Locations

Central contacts

Locations

Boston IVF

Recruiting

Boston, Massachusetts, United States, 02451

Contacts

More Information

Sponsor

Beth Israel Deaconess Medical Center

Last update posted

Apr 2, 2026

Last verified

Mar, 2026

Keywords

  • infertility
  • in vitro fertilization
  • cleavage stage embryo
  • blastocyst
  • embryo transfer

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Beth Israel Deaconess Medical Center on 2026-04-02.