An interventional study of Day 2 Fresh Embryo Transfer in POSEIDON Category 4, Low Prognosis in Assisted Reproductive Technology and Female Infertility Due to Diminished Ovarian Reserve, sponsored by Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University. Not yet recruiting. Open to female participants aged 35 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-04-16.
Sponsored by Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University · Not applicable, Interventional, and Treatment
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:
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:
Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University is the lead sponsor of 160 studies on the registry; 70 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
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.
Procedure: Day 2 Fresh Embryo Transfer
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.
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.
Live birth rate
Live birth rate, defined as the delivery of at least one neonate with heartbeat and breathing at ≥ 28 weeks of gestation.
Time frame: From enrollment to delivery
Congenital malformation rate
The proportion of participants who achieved a live birth and delivered a newborn diagnosed with a congenital malformation according to the International Classification of Diseases (ICD-10).
Time frame: From enrollment to 1 month after delivery
Low birth weight rate
The proportion of participants who achieved a live birth and delivered a newborn with a birth weight of less than 2500g.
Time frame: From enrollment to the delivery
Embryo utilization rate
The proportion of all obtained fertilized embryos (2PN zygotes) that are available for subsequent embryo transfer.
Time frame: Day 2 or Day 3 after oocyte retrieval
Moderate/severe OHSS incidence rate
The proportion of participants enrolled in the study who developed moderate or severe ovarian hyperstimulation syndrome (OHSS), meeting the criteria of the Royal College of Obstetricians and Gynaecologists (RCOG), between oocyte retrieval and 12 weeks of gestation.
Time frame: From oocyte retrieval to 12 weeks of gestation
Miscarriage rate
The proportion of participants who experienced a clinical pregnancy and subsequently had a spontaneous pregnancy loss before 28 weeks of gestation.
Time frame: From enrollment to ≤28 weeks of gestation
Clinical pregnancy rate
The proportion of participants enrolled in the study who experienced a clinical pregnancy, defined as the confirmation of an intrauterine gestational sac via ultrasound examination 28 days after embryo transfer.
Time frame: From enrollment to 28 days after embryo transfer
Implantation rate
The proportion of all transferred embryos that developed into an intrauterine gestational sac, as confirmed by ultrasound examination 28 days after embryo transfer.
Time frame: From enrollment to 28 days after embryo transfer
Rate of no available embryos
The proportion of participants enrolled in the study who, following ovarian stimulation, oocyte retrieval, and embryo culture, have no embryos available for transfer.
Time frame: Day 2 or Day 3 after oocyte retrieval
Biochemical pregnancy rate
The proportion of participants enrolled in the study who experienced a biochemical pregnancy, defined as a serum HCG level ≥25 IU/L measured 14 or 15 days after embryo transfer.
Time frame: From enrollment to 14 days (D3) or 15 days (D2) after embryo transfer
Preterm birth rate
The proportion of participants who achieved a live birth and delivered between 28 and 36⁺⁶ weeks of gestation.
Time frame: From enrollment to the delivery
Ongoing pregnancy rate
The proportion of participants enrolled in the study who experienced an ongoing pregnancy, defined as the confirmation of an intrauterine viable fetus via ultrasound examination at 12 weeks of gestation.
Time frame: From enrollment to 12 weeks of gestation
No study locations are listed for this record.
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes — De-identified individual participant data (IPD), along with the study protocol and statistical analysis plan, will be made publicly available via the National Clinical Research Data Sharing Platform (https://www.ncmc-data.org) within 12 months after study completion. The data will be accessible to qualified researchers in compliance with relevant laws, regulations, and ethical requirements.
Supporting information: Study protocol, Sap
This study is not yet recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University