The Impact of Assisted Hatching on Pregnancy Outcomes After Vitrified-Warmed Embryo Transfer in Advanced-age Patients
The Impact of Laser-Assisted Hatching on Pregnancy Outcomes After Vitrified-Warmed Embryo Transfer in Advanced-age Patients: A Randomized Controlled Trial
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interventional
916
0 countries
N/A
Brief Summary
The goal of this clinical trial is to evaluate the effect of laser assisted hatching (LAH) on pregnancy outcomes, with live birth rate as the primary outcome, in advanced age infertile women aged ≥35 years who are undergoing non-donor IVF/ICSI cycles and planning vitrified-warmed embryo transfer. It also aims to monitor the safety of LAH and assess various secondary pregnancy and neonatal outcomes. The main questions it aims to answer are: Does laser assisted hatching improve the live birth rate in advanced age women undergoing vitrified-warmed embryo transfer? Does laser assisted hatching affect secondary outcomes including implantation rate, biochemical pregnancy rate, clinical pregnancy rate, ectopic pregnancy rate, ongoing pregnancy rate, miscarriage rate, multiple pregnancy rate, preterm birth rate, and rates of obstetric and neonatal complications as well as congenital anomalies? Researchers will compare the Laser Assisted Hatching (LAH) Group to the Control Group (without LAH) to see if LAH can improve pregnancy outcomes in the study population. Participants will:
- Be randomly assigned to either the LAH Group or the Control Group at a 1:1 ratio, stratified by age (\<40 years/≥40 years) and embryo stage (cleavage stage/blastocyst) using stratified block randomization.
- Undergo the first or second frozen-thawed embryo transfer cycle, with transferred embryos meeting the quality criteria (cleavage-stage embryos: Grade I, Grade II, or CP and above; blastocysts: 4BC/CB and above).
- Receive embryo vitrification and warming after routine fertilization and culture; LAH Group will undergo LAH (thinning zona pellucida for cleavage-stage embryos, removing 1/4-1/3 of zona pellucida circumference for blastocysts) in G2 medium after embryo thawing, while Control Group will not receive assisted hatching.
- Have endometrial preparation by natural, ovulatory, or hormone replacement cycles as appropriate, and 1-2 viable embryos will be transferred under ultrasound guidance within 3 hours after thawing, followed by routine luteal support after transfer.
- Complete follow-up at multiple time points: 12-15 days after embryo transfer (serum β-hCG test), 28 days after embryo transfer (transvaginal ultrasound), 12 weeks of gestation (ultrasound), 28 weeks of gestation (ultrasound), and 1 month after delivery (collection of delivery and neonatal information).
- Provide demographic, clinical, and embryological baseline data, as well as various outcome data during the study period.
- Undergo regular monitoring of vital signs, laboratory test results, and adverse events, with key prevention and control of specific risks related to LAH such as embryo damage and multiple pregnancy.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for not_applicable
Started Mar 2026
Typical duration for not_applicable
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
March 16, 2026
CompletedFirst Submitted
Initial submission to the registry
March 18, 2026
CompletedFirst Posted
Study publicly available on registry
March 24, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
September 30, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
December 31, 2027
March 24, 2026
March 1, 2026
1.5 years
March 18, 2026
March 18, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Live birth rate
Live birth rate is defined as the proportion of all enrolled participants who achieved a live birth, defined as the delivery of a live infant at ≥28 weeks of gestation with any signs of life (e.g., heartbeat, respiration).
From enrollment to the delivery (≥28 weeks of gestation)
Secondary Outcomes (12)
Ongoing pregnancy rate
From enrollment to 12 weeks of gestation
Biochemical pregnancy rate
From enrollment to 12 days (blastocyst), 14 days (D3), or 15 days (D2) after embryo transfer
Ectopic pregnancy rate
From enrollment to 28 days after embryo transfer
Neonatal complication rate
From enrollment to 1 month after delivery
Macrosomia rate
From enrollment to the delivery
- +7 more secondary outcomes
Study Arms (2)
Laser Assisted Hatching (LAH) Group
EXPERIMENTALLaser assisted hatching will be performed on vitrified-warmed embryos prior to embryo transfer according to standard laboratory procedures. For cleavage-stage embryos, the zona pellucida will be thinned; for blastocysts, 1/4-1/3 of the zona pellucida circumference will be removed, and the operation will be performed in G2 medium after embryo thawing.
Control Group (No AH)
NO INTERVENTIONEmbryos will undergo routine vitrification-warming and preparation without assisted hatching prior to transfer, and will be transferred within 3 hours after thawing.
Interventions
Laser assisted hatching will be performed on vitrified-warmed embryos prior to embryo transfer according to standard laboratory procedures. For cleavage-stage embryos, the zona pellucida will be thinned; for blastocysts, 1/4-1/3 of the zona pellucida circumference will be removed, and the operation will be performed in G2 medium after embryo thawing.
Eligibility Criteria
You may qualify if:
- : Female age ≥ 35 years
- : First or second vitrified-warmed embryo transfer cycle
- : Quality of embryos for transfer meeting the criteria: Grade I, II, CP or above (cleavage-stage embryos); Grade 4BC/CB or above (blastocysts)
- : Provide written informed consent
You may not qualify if:
- : Use of donor oocytes or sperm, or planned preimplantation genetic testing (PGT)
- : Severe immune or chromosomal abnormalities
- : Uterine cavity abnormalities (i.e., adenomyosis, submucous uterine fibroids, hydrosalpinx, uterine septum, and endometrial polyps)
- : Embryos with an abnormal zona pellucida
- : Complicated with severe underlying diseases (e.g., uncontrolled hypertension/diabetes mellitus, active malignant tumors)
- : A history of recurrent implantation failure (≥2 cycles) or recurrent miscarriage (≥2 episodes)
Contact the study team to confirm eligibility.
Sponsors & Collaborators
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- SINGLE
- Who Masked
- OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
March 18, 2026
First Posted
March 24, 2026
Study Start
March 16, 2026
Primary Completion (Estimated)
September 30, 2027
Study Completion (Estimated)
December 31, 2027
Last Updated
March 24, 2026
Record last verified: 2026-03
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, SAP
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.