An improved mechanical technique for assisted hatching
Open Access
- 28 April 2005
- journal article
- research article
- Published by Oxford University Press (OUP) in Human Reproduction
- Vol. 20 (6), 1619-1623
- https://doi.org/10.1093/humrep/deh809
Abstract
BACKGROUND: Varied clinical outcomes of assisted hatching (AH) have been reported. We attempt to investigate whether the size of the zona opening created by AH is adequate for blastocyst hatching, and, if not, set up a new method to improve it. METHODS: A new AH technique, long zona dissection (LZD), was established, and experiments were performed to compare the effects of different sizes of zona opening on complete hatching of blastocysts in mouse and human embryos in vitro. RESULTS: The LZD technique can create a long zona slit on early embryos, even blastocysts, with the slit size beyond two-thirds of zona diameter. Compared with three-dimensional partial zona dissection, LZD can significantly enhance the hatching speed and the rate of complete hatching of mouse blastocysts (93.9%). All (100%) human blastocysts completely hatched following LZD; however, when the slit size after AH was about two-fifths of zona diameter, more of the larger inner cell masses (ICM) became trapped by the zona opening during hatching than the smaller ICM (53.3 versus 12.5%, P=0.01). CONCLUSIONS: Zona opening of moderate size following AH is inadequate for the completion of blastocyst hatching in vitro; in some cases, however, it can be significantly improved by LZD.Keywords
This publication has 17 references indexed in Scilit:
- Laser zona pellucida thinning—an alternative approach to assisted hatchingHuman Reproduction, 2001
- Analysis of the human zona pellucida during culture: Correlation with diagnosis and the preovulatory hormonal environmentJournal of Assisted Reproduction and Genetics, 1997
- Assisted hatching by zona drilling of human embryos in women of advanced ageHuman Reproduction, 1997
- Fertilization and early embrology: Monozygotic twinning in the human is associated with the zona pellucida architectureHuman Reproduction, 1994
- Implantation enhancement by selective assisted hatching using zona drilling of human embryos with poor prognosisHuman Reproduction, 1992
- Effects of the size and number of zona pellucida openings on hatching and trophoblast outgrowth in the mouse embryoMolecular Reproduction and Development, 1991
- Assisted hatching of human embryosJournal of Assisted Reproduction and Genetics, 1991
- Freeze-thaw-induced changes of the zona pellucida explains decreased rates of fertilization in frozen-thawed mouse oocytesReproduction, 1990
- Impairment of the hatching process following IVF in the human and improvement of implantation by assisting hatching using micromanipulationHuman Reproduction, 1990
- “Spontaneous” hardening of the zona pellucida of mouse oocytes during in vitro cultureGamete Research, 1982