An interventional study of Laser-Assisted Hatching in Infertility; In Vitro Fertilization; Embryo Development, sponsored by Hoang Minh Ngan. Completed at 1 site in Vietnam. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-10.
Sponsored by Hoang Minh Ngan · Not applicable, Interventional, and Treatment
This randomized controlled trial compared assisted hatching (AH) performed on Day 3 versus Day 5 in patients undergoing IVF-ICSI with preimplantation genetic testing for aneuploidy (PGT-A). Eligible IVF-ICSI cycles were randomly assigned to one of the two AH strategies, and all embryos from each randomized cycle followed the assigned strategy. The study evaluated whether the timing of AH was associated with differences in blastocyst development, blastocyst morphology, and PGT-A outcomes. The findings are intended to help optimize the timing of assisted hatching in IVF laboratory practice.
This prospective randomized controlled trial compared two standardized assisted-hatching strategies in IVF-ICSI cycles undergoing preimplantation genetic testing for aneuploidy (PGT-A). Eligible IVF-ICSI cycles were randomly allocated in a 1:1 ratio to Day-3 assisted hatching (Arm A) or Day-5 assisted hatching (Arm B). Randomization was performed at the IVF-ICSI cycle level using fixed block randomization with a block size of 4. Randomization was not stratified by maternal age, anti-Müllerian hormone level, or other clinical characteristics. Women who underwent more than one eligible IVF-ICSI cycle could contribute more than one randomized cycle, with each eligible cycle assigned according to the randomization sequence. All embryos derived from each randomized cycle followed the assigned assisted-hatching strategy.
In Arm A, laser-assisted hatching was performed on Day-3 embryos. In Arm B, laser-assisted hatching was performed on Day-5 blastocysts. In both groups, blastocysts were evaluated on Day 5 and subsequently cultured for approximately 6-7 additional hours before trophectoderm biopsy. This interval was standardized across both study arms and was consistent with the routine laboratory workflow, while allowing additional time for blastocyst expansion and hatching before biopsy. Blastocyst morphology used for the primary morphological analyses was assessed at the time of trophectoderm biopsy according to standardized criteria, including blastocyst expansion stage, inner cell mass (ICM) morphology, and trophectoderm (TE) morphology.
Blastocysts meeting biopsy criteria underwent trophectoderm biopsy followed by PGT-A using next-generation sequencing. PGT-A was performed using paired-end sequencing with the EmbryoMap™ Kit (Vitrolife) on the Illumina MiSeq sequencing system. PGT-A testing and interpretation were conducted by a separate genetics laboratory whose analysts were blinded to the assisted-hatching allocation.
A total of 141 women contributed 158 randomized IVF-ICSI cycles to the study, with 79 cycles allocated to Day-3 assisted hatching and 79 cycles allocated to Day-5 assisted hatching. Sixteen women contributed more than one IVF-ICSI cycle: 15 women contributed two cycles and one woman contributed three cycles. Statistical analyses accounted for within-participant correlation arising from repeated IVF-ICSI cycles and multiple embryos contributed by the same woman, where appropriate.
Participants and treating clinicians were unaware of the assigned assisted-hatching timing. The embryologist performing assisted hatching could not be blinded at the time of the intervention because knowledge of the assigned timing was required to perform the procedure.
2,085 studies on the registry are indexed under Infertility; 357 are open to participants now.
This study's enrollment of 141 is close to the median of 135 across 1,412 interventional studies indexed under Infertility.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Laser-assisted hatching was performed on Day-3 embryos according to the standardized laboratory protocol. Embryos were then cultured to the blastocyst stage. On Day 5, blastocysts were evaluated and cultured for approximately 6-7 additional hours before trophectoderm biopsy for PGT-A.
Procedure: Laser-Assisted Hatching
Embryos were cultured without assisted hatching until Day 5. Laser-assisted hatching was then performed on Day-5 blastocysts according to the standardized laboratory protocol. Blastocysts were subsequently cultured for approximately 6-7 additional hours before trophectoderm biopsy for PGT-A.
Procedure: Laser-Assisted Hatching
A standardized laser-assisted opening of the zona pellucida was performed either on Day 3 or Day 5 according to randomized group assignment. The only protocol-defined difference between study arms was the timing of assisted hatching; subsequent blastocyst culture, Day-5 assessment, and trophectoderm biopsy procedures were standardized across both groups.
Also known as: Assisted Hatching (AH), Laser-Assisted Hatching (LAH)
Distribution of PGT-A Genetic Classifications
Blastocysts with a valid PGT-A result were classified into three mutually exclusive categories: euploid, mosaic, or abnormal. The distribution of these three PGT-A classifications was compared between the Day-3 and Day-5 assisted-hatching groups.
Time frame: Following PGT-A of blastocysts biopsied on Day 5 or Day 6 of embryo culture
Blastocyst Morphology at Trophectoderm Biopsy
Blastocyst morphology was assessed at the time of trophectoderm biopsy using standardized criteria, including blastocyst expansion stage, inner cell mass (ICM) morphology, and trophectoderm (TE) morphology. The distributions of these morphological characteristics were compared between the Day-3 and Day-5 assisted-hatching groups.
Time frame: At trophectoderm biopsy on Day 5 or Day 6 of embryo culture
Proportion of Mosaic Blastocysts
Blastocysts with a valid PGT-A result were classified as euploid, mosaic, or abnormal. The proportion of blastocysts classified as mosaic was calculated for each assisted-hatching group, using the number of blastocysts with a valid PGT-A result as the denominator.
Time frame: Following PGT-A of blastocysts biopsied on Day 5 or Day 6 of embryo culture
Association Between Blastocyst Morphology and PGT-A Classification
The association between blastocyst morphology at trophectoderm biopsy, including blastocyst expansion stage, inner cell mass (ICM) morphology, and trophectoderm (TE) morphology, and PGT-A classification as euploid, mosaic, or abnormal was evaluated.
Time frame: Blastocyst morphology at trophectoderm biopsy on Day 5 or Day 6, with subsequent PGT-A classification
Plan to share: No — The plan for sharing individual participant data (IPD) has not yet been finalized. De-identified participant- and embryo-level data may be considered for sharing upon reasonable request for academic research, subject to applicable ethical, institutional, and data-protection requirements.
This study is completed, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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