Day-4 Embryo Defragmentation: Blastocyst Rate and clInical Outcomes
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexFemale
Age20-42
SponsorMomo Fertilife
About this trial
Background:
Embryo fragmentation is one of the main morphological parameters assessed during in vitro culture in assisted reproductive technology (ART). The presence of anucleate cytoplasmic fragments is commonly observed in human embryos and may negatively affect developmental potential and clinical outcomes. Embryo defragmentation at early stages (Day 2-3) is an established technique in some centers, but evidence remains heterogeneous. Defragmentation at Day 4 (morula/compaction stage) represents a significantly less explored area, with promising but insufficient data to guide clinical practice.
Study Objective:
This study aims to evaluate whether mechanical or laser-assisted embryo defragmentation performed on Day 4 (D4) of in vitro culture improves blastocyst development rates and clinical outcomes in ART cycles, compared to standard culture without intervention.
Study Design:
This is a prospective, randomized controlled trial (RCT) with single-blind assessment. Patients undergoing IVF/ICSI with embryos showing ≥10% fragmentation at D4 morphological evaluation will be randomly assigned (1:1 ratio) to one of two groups:
Group A (Intervention): Mechanical/laser defragmentation at D4, followed by standard blastocyst culture Group B (Control): Standard blastocyst culture without any additional manipulation
Randomization will be performed at the patient level using pre-generated block randomization lists, stratified by patient age (\<35 vs. ≥35 years), number of fragmented embryos at D4, and use of preimplantation genetic testing (PGT-A).
Participants:
Women aged 18-43 years undergoing IVF/ICSI cycles, with at least one embryo showing ≥10% fragmentation at D4 and destined for blastocyst culture. Key exclusion criteria include: donor gamete cycles, PGT-M as primary indication, embryos with \>50% fragmentation, or severe morphological compromise at Day 3.
Primary Outcome:
Rate of usable blastocysts (Gardner score ≥3BB) per embryo included in the study, assessed at Day 5 and Day 6 of culture.
Secondary Outcomes:
Overall blastocyst development rate (D5/D6), Gardner score distribution, blastocyst cryopreservation rate, implantation rate, clinical pregnancy rate (heartbeat at 7 weeks), ongoing pregnancy rate (beyond 12 weeks), live birth rate per transfer, and morphokinetic analysis (if time-lapse incubator available).
Sample Size:
Approximately 240 patients total (120 per arm), based on an expected blastocyst rate of \~42% in the control group vs. \~57% in the intervention group (15% absolute difference), with 80% power and α=0.05. A 15% dropout correction is applied.
Duration:
6 months of enrollment plus 6 months of clinical follow-up (total \~12 months).
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Female patients undergoing ICSI cycles at the participating center
Age 18-42 years
Presence of at least one morula with cytoplasmic fragmentation ≥10% at Day 4 morphological assessment (Grade B: 10-25%, Grade C: 26-50%, Grade D: ≥50%)
Embryos intended for extended culture to blastocyst stage (Day 5/Day 6)
Disqualifiers
Severely reduced ovarian reserve (AMH ≤ 0.5 ng/mL)
Body mass index (BMI) ≥ 32 kg/m²
Diagnosis of endometriosis
Polycystic ovary syndrome (PCOS)
Trial design
Design model
Parallel
Treatments tested in this trial
Mechanical embryo defragmentation at Day 4 (morula stage)
Procedure/SurgeryMicrosurgical aspiration of cytoplasmic fragments from morulae with ≥10% fragmentation, performed on Day 4 of embryo development (96 ± 2 hours post-ICSI), when blastomeres are already compacting and fragments are clearly distinguishable from the compact cell mass. A diode laser (1.48 µm wavelength) is used to breach the zona pellucida, followed by fragment aspiration using a 35 µm biopsy needle mounted on a hydraulic oil microinjection system. Fragments of softer consistency are aspirated directly; harder fragments are anchored with the needle spike and mechanically extracted. The procedure is performed on a heated stage at 37°C using HEPES-buffered medium (G-MOPS Plus, Vitrolife), with a maximum manipulation time of 10 minutes per patient. All embryos are cultured in a time-lapse incubator (Geri, Genea Biomedex) under controlled atmosphere (6% CO2, 5% O2) throughout the study.
Standard embryo culture without intervention
Other interventionStandard blastocyst culture without any additional manipulation. Day 4 morphological assessment is performed under the same conditions as the intervention group to ensure comparability of culture conditions.
Standard embryo culture without intervention
Other interventionStandard blastocyst culture without any additional manipulation. Day 4 morphological assessment is performed under the same conditions as the intervention group to ensure comparability of culture conditions.
Treatment groups
320 Participants
are divided into 3 treatment groupsGroup A: D4 Non-Defragmented GroupSham comparator 1 intervention
Group B: D4 Defragmented GroupExperimental treatment 1 intervention
Group C: Control Group (Low Fragmentation)Active comparator 1 intervention
Trial outcomes
Primary outcomes
1
Clinical pregnancy rate
Rate of positive beta-hCG tests 12-14 days after single blastocyst transfer, confirmed by transvaginal ultrasound showing gestational sac and fetal viability at 4 weeks post-transfer.
Time frame
4 weeks post-embryo transferSecondary outcomes
1
Blastocyst formation rate
Rate of blastocysts (any quality) developed from morulae at Day 5/Day 6, calculated as number of blastocysts divided by number of morulae included in the study. Assessed by a blinded embryologist.
Time frame
Day 5 and Day 6 post-fertilizationSponsors and contacts
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Source ClinicalTrials.gov