Laser zona pellucida thinning—an alternative approach to assisted hatching

Blake, Debbie; Forsberg, Ann-Sofie; Johansson, Bengt R.; Wikland, Matts

doi:10.1093/humrep/16.9.1959

Cited by 80 publications

(57 citation statements)

References 29 publications

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“…More recently, Blake et al [56] demonstrated a significant increase in hatching in vitro, using the laser to thin the zona pellucida without creating a hole. A further study found a higher clinical pregnancy rate when using the laser to thin an extended area of the zona pellucida compared with producing a single full thickness hole [57].…”

Section: Laser-assisted Hatchingmentioning

confidence: 99%

Assisted hatching in assisted reproduction: a state of the art

Hammadeh

Fischer-Hammadeh

Ali

2010

J Assist Reprod Genet

106

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The World Health Organization estimates that one in six couples experience some delay in conception and an increasing number require treatment by the assisted conception (AC) procedures of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).The implantation rate of embryos resulting from in vitro fertilization cycles is generally less than 20%. The exposure of oocytes and embryos to the artificial conditions of in vitro culture may have negative effects on the embryo's ability to undergo normal hatching, resulting in low rates of implantation following IVF and embryo transfer. Human embryos resulting from superovulation develop more slowly in vitro compared to embryos in vivo, manifest a relatively high degree of cytogenetic abnormalities and undergo cellular fragmentation. Artificially disrupting the zona pellucida is known as assisted hatching (AH) and there is some evidence that embryos that have undergone zona manipulation for assisted hatching tend to implant one day earlier than unhatched embryos. A variety of techniques have since been employed to assist embryo hatching, including partial mechanical zona dissection, zona drilling and zona thinning, making use of acid tyrodes, proteinases, piezon vibrator manipulators and lasers. This review will consider the impact of IVF conditions on zona pellucida physiology, zona hardening, different techniques of assisted hatching, who may benefit from assisted hatching and potential hazards.

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Section: Laser-assisted Hatchingmentioning

confidence: 99%

Assisted hatching in assisted reproduction: a state of the art

Hammadeh

Fischer-Hammadeh

Ali

2010

J Assist Reprod Genet

106

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“…LAH can improve the clinical pregnancy rate of the thawing cycle. Since LAH can be divided into artificial thinning of the zona and drilling of the zona, previous findings have shown that the former is better than that the latter in vitro (15,16). Hiraoka et al have shown that vitrification can increase the hardness of zona, and the embryo implantation and clinical pregnancy rates in the half ZP thinning FET cycle was superior to that of a quarter ZP, although these studies lacked a control group (1).…”

Section: Introductionmentioning

confidence: 99%

Outcomes of vitrified-warmed cleavage-stage embryo hatching after in vitro laser-assisted zona pellucida thinning in patients

Wang¹,

Wang

et al. 2016

Biomedical Reports

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Abstract. The aim of the present study was to determine whether the size of the zona pellucida (ZP) thinning area by laser-assisted hatching affected the potential development of vitrified-warmed embryos. A total of 196 vitrified-warmed cleavage-stage embryos (from 49 patients, four sister embryos per patient) were used in the study, i.e., four sister embryos from each patient were randomly assigned to four groups: A control group of embryos that were not zona-manipulated (zona intact, group A); one experimental group of embryos in which a quarter of the zona pellucida was thinned using laser-assisted ZP thinning (group B); a second experimental group of embryos in which half of ZP was thinned (group C); and a third group in which two-thirds of the ZP was thinned (group D). Subsequent blastocyst development was assessed. Microscopy was performed to study the hatching process of the embryos after zona thinning. The blastocyst formation rates were 71.43% in group A, 67.35% in group B, 65.31% in group C, and 51.02% in group D (groups B-D vs. group A, P=0.661, P=0.515, P= 0.038, respectively). The rates of complete hatching were 30.61% in group A, 38.78% in group B, 61.22% in group C, and 48.98% in group D (groups B-D vs. group A, P= 0.396, P= 0.002, P= 0.063, respectively). For a subgroup of patients, there was a significant difference in the complete hatching in all the groups for women aged <35 years (P=0.011), and there was a significant difference in the complete hatching in all the groups for secondary infertility women (P=0.022). There was no significant difference in the blastocyst formation rates in the different groups of women aged ≥35 years (P= 0.340). In addition, there was no significant difference in the complete hatching in the different groups among women aged ≥35 years (P= 0.492). The results of the present study showed that in vitrified-warmed embryo transfers at the cleavage-stage, and the two-thirds zona pellucida thinning group demonstrated a significantly decreased blastocyst formation rate compared with the control group, while the half zona pellucida thinning group demonstrated a significantly increased complete hatching rate compared with the control group, which may have a high value in clinical application.

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“…Mechanical ZP dissection with glass pipettes [7] or chemical ZP opening using acidic Tyrode's solution [8,9] are in wide use. Recently, AH by 1.48 μm diode laser has been introduced and has enabled to reliably produce equally sized ZP opening [10][11][12][13]. However, studies evaluating the effect of the size of ZP opening by laser AH for frozen cleaved embryos are lacking.…”

Section: Introductionmentioning

confidence: 99%

“…However, studies evaluating the effect of the size of ZP opening by laser AH for frozen cleaved embryos are lacking. One reason for this may be due to the fear that opening the ZP at the cleavage stage may have adverse effect such as loss of blastomeres through the opened ZP [11,12]. This problem can be overcome by performing AH at the blastocyst stage.…”

Section: Introductionmentioning

confidence: 99%