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Day 2 versus Day 3 embryo transfer in women with low fertility prognosis

Compares embryo transfer on Day 2 or Day 3 in women with diminished ovarian reserve.

Key facts

Who runs it
Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University
Trial code
Registry title
Impact of Day 2 Versus Day 3 Fresh Embryo Transfer on Live Birth Rate in Poor-Prognosis Patients
Status
Not yet recruiting
People taking part
470 people, planned
Started
30 Mar 2026
Expected to end
31 Dec 2027
Type of study
Interventional, 2 groupsOne group gets no study treatment, for comparison.
Treatments tested
  • Day 2 Fresh Embryo Transfer
Record updated
16 April 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for women aged 35 or older with a low egg reserve who are having IVF/ICSI. It compares putting a fresh embryo back on Day 2 versus Day 3.

Age
35 Years to 50 Years
Sex
Women only
Disease stage
POSEIDON Category 4 low prognosis: age ≥ 35 years with a low egg reserve. Must be in a first or second IVF/ICSI cycle.
Earlier treatment
Must be having ovarian stimulation with a GnRH antagonist protocol, with at least 1 egg (oocyte) collected.
Biomarker or test result
Antral follicle count (AFC) < 5 or anti-Müllerian hormone (AMH) < 1.2 ng/mL. Progesterone must not be > 1.5 ng/mL on the hCG trigger day.

Main reasons for not taking part

  • Use of donor eggs or sperm, or planned genetic testing of embryos (PGT)
  • Severe immune or chromosome problems
  • Problems of the womb cavity, such as submucous fibroids, a complete uterine septum or severe scarring, or an untreated, ultrasound-visible fluid-filled fallopian tube
  • Severe other diseases, such as uncontrolled high blood pressure or diabetes, or active cancer
  • Embryos failed to implant in ≥2 cycles, or ≥2 miscarriages in the past

The registry criteria, word for word

Show all 10 criteriaShow less

Who can take part

  • 1: Meet the definition of POSEIDON Category 4: age ≥ 35 years, with antral follicle count (AFC) < 5 or anti-Müllerian hormone (AMH) < 1.2 ng/mL
  • 2: Undergoing first or second IVF/ICSI cycle
  • 3: Undergoing controlled ovarian hyperstimulation (COH) using a gonadotropin-releasing hormone (GnRH) antagonist protocol, with at least 1 oocyte retrieved
  • 4: Provide written informed consent

Who cannot take part

  • 4: Presence of severe underlying diseases (e.g., uncontrolled hypertension/diabetes mellitus, active malignant tumors)
  • 5: History of recurrent implantation failure (≥2 cycles) or recurrent miscarriage (≥2 episodes)
  • 1: Use of donor oocytes/sperm, or planned preimplantation genetic testing (PGT)
  • 2: Severe immune or chromosomal abnormalities
  • 3: Uterine cavity abnormalities (i.e., submucous fibroids, complete uterine septum, severe intrauterine adhesions, etc.) or untreated, ultrasound-visible hydrosalpinx
  • 6: Progesterone level > 1.5 ng/mL on the day of human chorionic gonadotropin (hCG) trigger

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 35 and 50 years old?

About the trial

What the trial wants to find out

This study aimed to compare the efficacy (live birth rate) of fresh embryo transfer on Day 2 versus Day 3 in POSEIDON Group 4 patients, and to determine the optimal timing of embryo transfer for this population. It is a single-center, parallel-group, open-label prospective randomized controlled trial, and outcome assessors are masked. The main questions it aims to answer are:

Read full original descriptionShow less

Is there a significant difference in the live birth rate between Day 2 and Day 3 fresh embryo transfer in patients with POSEIDON Category 4 low prognosis? What are the differences in secondary outcomes (including clinical pregnancy rate, ongoing pregnancy rate, implantation rate, embryo utilization rate, miscarriage rate, incidence of moderate/severe OHSS, and adverse neonatal outcomes) between the two embryo transfer timings, and which timing is safer and more effective for this patient population?

A total of 470 patients meeting the POSEIDON Category 4 criteria will be enrolled and randomly assigned to the Day 2 Fresh Embryo Transfer Group and the Day 3 Fresh Embryo Transfer Group in a 1:1 ratio using stratified block randomization. Researchers will compare the two groups to clarify the difference in live birth rate (primary outcome) and other secondary outcomes, so as to determine the optimal embryo transfer timing.

Participants will:

* Be female patients aged ≥ 35 years with antral follicle count (AFC) < 5 or anti-Müllerian hormone (AMH) < 1.2 ng/mL, undergoing the first or second IVF/ICSI cycle, receiving controlled ovarian hyperstimulation (COH) with the GnRH antagonist protocol, and having ≥ 1 oocyte retrieved (excluding those using donor oocytes/sperm, with uterine cavity abnormalities, or complicated with severe underlying diseases). * Be randomly assigned to either the Day 2 Fresh Embryo Transfer Group or the Day 3 Fresh Embryo Transfer Group, and receive embryo transfer according to the corresponding group's protocol * Receive routine luteal support treatment after embryo transfer * Attend follow-up visits at multiple time points (on the day of transfer, 12-15 days after transfer, 28 days after transfer, during pregnancy, and after delivery) to collect relevant clinical and laboratory data for outcome assessment. * Undergo safety evaluation throughout the study; the study will adopt intention-to-treat (ITT) as the main statistical method and per-protocol (PP) as the sensitivity analysis, with subgroup analysis by age, AMH level, and number of oocytes retrieved, following ethical norms and data quality control requirements.

The 2 groups in the trial

  • D2 Embryo Transfer GroupTreatment being tested

    Embryos will be cultured for 44-48 hours after oocyte retrieval (Day 2), and embryos with ≥ 2 cells, grade II or above, and no multinucleation will be selected for transfer, with 1-2 embryos transferred; routine luteal support treatment will be given after transfer.

    Treatment: Day 2 Fresh Embryo Transfer

  • D3 Embryo Transfer GroupNo study treatment, for comparison

    Embryos will be cultured for 68-72 hours after oocyte retrieval (Day 3), and embryos with ≥ 6 cells, grade II or above, and no multinucleation will be selected for transfer, with 1-2 embryos transferred; routine luteal support treatment will be given after transfer.

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Impact of Day 2 Versus Day 3 Fresh Embryo Transfer on Live Birth Rate in Poor-Prognosis POSEIDON Group 4 Patients: A Single-Center, Parallel-Group, Open-Label Randomized Controlled Trial
Plain-language title
Day 2 versus Day 3 embryo transfer in women with low fertility prognosisGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 15 November 2026.
Fit questions
Built from NCT07533695, who can take part
Record updated
16 April 2026