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Meta-Analysis
. 2021 Mar 17;3(3):CD001894.
doi: 10.1002/14651858.CD001894.pub6.

Assisted hatching on assisted conception (in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI))

Lauren Lacey  1 , Sibte Hassan  2 , Sebastian Franik  3 , Mourad W Seif  4 , M Ahsan Akhtar  5
Affiliations
Meta-Analysis

Assisted hatching on assisted conception (in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI))

Lauren Lacey et al. Cochrane Database Syst Rev. .

Abstract

Background: Failure of implantation and conception may result from inability of the blastocyst to escape from its outer coat, which is known as the zona pellucida. Artificial disruption of this coat is known as assisted hatching and has been proposed as a method for improving the success of assisted conception by facilitating embryo implantation.

Objectives: To determine effects of assisted hatching (AH) of embryos derived from assisted conception on live birth and multiple pregnancy rates. SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility Group Specialised Register (until May 2020), the Cochrane Central Register of Controlled Trials (CENTRAL; until May 2020), in the Cochrane Library; MEDLINE (1966 to May 2020); and Embase (1980 to May 2020). We also searched trial registers for ongoing and registered trials (http://www.clinicaltrials.gov - a service of the US National Institutes of Health; http://www.who.int/trialsearch/Default.aspx - The World Health Organization International Trials Registry Platform search portal) (May 2020).

Selection criteria: Two review authors identified and independently screened trials. We included randomised controlled trials (RCTs) of AH (mechanical, chemical, or laser disruption of the zona pellucida before embryo replacement) versus no AH that reported live birth or clinical pregnancy data.

Data collection and analysis: We used standard methodological procedures recommended by Cochrane. Two review authors independently performed quality assessments and data extraction.

Main results: We included 39 RCTs (7249 women). All reported clinical pregnancy data, including 2486 clinical pregnancies. Only 14 studies reported live birth data, with 834 live birth events. The quality of evidence ranged from very low to low. The main limitations were serious risk of bias associated with poor reporting of study methods, inconsistency, imprecision, and publication bias. Five trials are currently ongoing. We are uncertain whether assisted hatching improved live birth rates compared to no assisted hatching (odds ratio (OR) 1.09, 95% confidence interval (CI) 0.92 to 1.29; 14 RCTs, N = 2849; I² = 20%; low-quality evidence). This analysis suggests that if the live birth rate in women not using assisted hatching is about 28%, the rate in those using assisted hatching will be between 27% and 34%. Analysis of multiple pregnancy rates per woman showed that in women who were randomised to AH compared with women randomised to no AH, there may have been a slight increase in multiple pregnancy rates (OR 1.38, 95% CI 1.13 to 1.68; 18 RCTs, N = 4308; I² = 48%; low-quality evidence). This suggests that if the multiple pregnancy rate in women not using assisted hatching is about 9%, the rate in those using assisted hatching will be between 10% and 14%. When all of the included studies (39) are pooled, the clinical pregnancy rate in women who underwent AH may improve slightly in comparison to no AH (OR 1.20, 95% CI 1.09 to 1.33; 39 RCTs, N = 7249; I² = 55%; low-quality evidence). However, when a random-effects model is used due to high heterogeneity, there may be little to no difference in clinical pregnancy rate (P = 0.04). All 14 RCTs that reported live birth rates also reported clinical pregnancy rates, and analysis of these studies illustrates that AH may make little to no difference in clinical pregnancy rates when compared to no AH (OR 1.07, 95% CI 0.92 to 1.25; 14 RCTs, N = 2848; I² = 45%). We are uncertain about whether AH affects miscarriage rates due to the quality of the evidence (OR 1.13, 95% CI 0.82 to 1.56; 17 RCTs, N = 2810; I² = 0%; very low-quality evidence).

Authors' conclusions: This update suggests that we are uncertain of the effects of assisted hatching (AH) on live birth rates. AH may lead to increased risk of multiple pregnancy. The risks of complications associated with multiple pregnancy may be increased without evidence to demonstrate an increase in live birth rate, warranting careful consideration of the routine use of AH for couples undergoing in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). AH may offer a slightly increased chance of achieving a clinical pregnancy, but data quality was of low grade. We are uncertain about whether AH influences miscarriage rates.

Trial registration: ClinicalTrials.gov NCT02752568.

PubMed Disclaimer

Conflict of interest statement

MAA, SF, SH and LL have no interests to declare. MS has received travel and accommodation support for conferences unrelated to the topic of this review.

Figures

1
1
Study flow diagram.
2
2
Methodological quality graph: review authors' judgements about each methodological quality item presented as percentages across all included studies.
3
3
Methodological quality summary: review authors' judgements about each methodological quality item for each included study.
4
4
Forest plot of comparison: 1 Live birth rate, outcome: 1.1 Live birth per woman randomised.
5
5
Funnel plot of comparison: 1 Live birth: assisted hatching compared with no assisted hatching, outcome: 1.1 Live birth per woman randomised.
6
6
Forest plot of comparison: 4 Multiple pregnancy rate, outcome: 4.1 Multiple pregnancy rate per woman randomised.
7
7
Forest plot of comparison: 2 Clinical pregnancy, outcome: 2.1 Clinical pregnancy rate per woman randomised.
8
8
Funnel plot of comparison: 3 Clinical pregnancy: assisted hatching compared with no assisted hatching, outcome: 3.1 Clinical pregnancy rate per woman randomised.
9
9
Funnel plot of comparison: 4 Clinical pregnancies in trials that reported live births: assisted hatching compared with no assisted hatching, outcome: 4.1 Clinical pregnancies in trials reporting live births.
10
10
Forest plot of comparison: 3 Miscarriage rate, outcome: 3.1 Miscarriage per woman randomised.
11
11
Forest plot of comparison: 5 Monozygotic twinning rate, outcome: 5.1 Monozygotic twinning per woman randomised.
1.1
1.1. Analysis
Comparison 1: Live birth: assisted hatching compared with no assisted hatching, Outcome 1: Live birth per woman randomised
1.2
1.2. Analysis
Comparison 1: Live birth: assisted hatching compared with no assisted hatching, Outcome 2: First or repeat attempt
1.3
1.3. Analysis
Comparison 1: Live birth: assisted hatching compared with no assisted hatching, Outcome 3: Conception mode
1.4
1.4. Analysis
Comparison 1: Live birth: assisted hatching compared with no assisted hatching, Outcome 4: Hatching method
1.5
1.5. Analysis
Comparison 1: Live birth: assisted hatching compared with no assisted hatching, Outcome 5: Prognosis
1.6
1.6. Analysis
Comparison 1: Live birth: assisted hatching compared with no assisted hatching, Outcome 6: Live birth rate by extent of assisted hatching
1.7
1.7. Analysis
Comparison 1: Live birth: assisted hatching compared with no assisted hatching, Outcome 7: Fresh or frozen embryo transfer
2.1
2.1. Analysis
Comparison 2: Multiple pregnancy: assisted hatching compared with no assisted hatching, Outcome 1: Multiple pregnancy rate per woman randomised
2.2
2.2. Analysis
Comparison 2: Multiple pregnancy: assisted hatching compared with no assisted hatching, Outcome 2: First or repeat attempt
2.3
2.3. Analysis
Comparison 2: Multiple pregnancy: assisted hatching compared with no assisted hatching, Outcome 3: Conception mode
2.4
2.4. Analysis
Comparison 2: Multiple pregnancy: assisted hatching compared with no assisted hatching, Outcome 4: Hatching method
2.5
2.5. Analysis
Comparison 2: Multiple pregnancy: assisted hatching compared with no assisted hatching, Outcome 5: Prognosis
2.6
2.6. Analysis
Comparison 2: Multiple pregnancy: assisted hatching compared with no assisted hatching, Outcome 6: Multiple pregnancy rate per woman grouped by extent of assisted hatching
2.7
2.7. Analysis
Comparison 2: Multiple pregnancy: assisted hatching compared with no assisted hatching, Outcome 7: Fresh or frozen embryo transfer
2.8
2.8. Analysis
Comparison 2: Multiple pregnancy: assisted hatching compared with no assisted hatching, Outcome 8: Multiple pregnancy per pregnancy
3.1
3.1. Analysis
Comparison 3: Clinical pregnancy: assisted hatching compared with no assisted hatching, Outcome 1: Clinical pregnancy rate per woman randomised
3.2
3.2. Analysis
Comparison 3: Clinical pregnancy: assisted hatching compared with no assisted hatching, Outcome 2: First or repeat attempt
3.3
3.3. Analysis
Comparison 3: Clinical pregnancy: assisted hatching compared with no assisted hatching, Outcome 3: Conception mode
3.4
3.4. Analysis
Comparison 3: Clinical pregnancy: assisted hatching compared with no assisted hatching, Outcome 4: Hatching method
3.5
3.5. Analysis
Comparison 3: Clinical pregnancy: assisted hatching compared with no assisted hatching, Outcome 5: Prognosis
3.6
3.6. Analysis
Comparison 3: Clinical pregnancy: assisted hatching compared with no assisted hatching, Outcome 6: Extent of assisted hatching
3.7
3.7. Analysis
Comparison 3: Clinical pregnancy: assisted hatching compared with no assisted hatching, Outcome 7: Fresh and frozen embryo transfer
4.1
4.1. Analysis
Comparison 4: Clinical pregnancies in trials that reported live births: assisted hatching compared with no assisted hatching, Outcome 1: Clinical pregnancies in trials reporting live births
5.1
5.1. Analysis
Comparison 5: Miscarriage: assisted hatching compared with no assisted hatching, Outcome 1: Miscarriage per woman randomised
5.2
5.2. Analysis
Comparison 5: Miscarriage: assisted hatching compared with no assisted hatching, Outcome 2: First or repeat attempt
5.3
5.3. Analysis
Comparison 5: Miscarriage: assisted hatching compared with no assisted hatching, Outcome 3: Conception mode
5.4
5.4. Analysis
Comparison 5: Miscarriage: assisted hatching compared with no assisted hatching, Outcome 4: Hatching method
5.5
5.5. Analysis
Comparison 5: Miscarriage: assisted hatching compared with no assisted hatching, Outcome 5: Prognosis
5.6
5.6. Analysis
Comparison 5: Miscarriage: assisted hatching compared with no assisted hatching, Outcome 6: Miscarriage per clinical pregnancy
6.1
6.1. Analysis
Comparison 6: Monozygotic twinning: assisted hatching compared with no assisted hatching, Outcome 1: Monozygotic twinning per woman randomised
7.1
7.1. Analysis
Comparison 7: Robust studies (randomisation method and allocation concealment stated and live birth reported): assisted hatching compared with no assisted hatching, Outcome 1: Live births
7.2
7.2. Analysis
Comparison 7: Robust studies (randomisation method and allocation concealment stated and live birth reported): assisted hatching compared with no assisted hatching, Outcome 2: Clinical pregnancies
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References

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Domitrz 2000 {published data only}
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Ebner 2002 {published data only}
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Feng 2009 {published data only}
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Figueira 2012 {published data only}
    1. Braga DPAF, Figueira RCS, Setti AS, Colturato SS, Iaconelli A Jr, Borges E Jr. Relevância do assited hatching com laser em um programa de ovo-doação utilizando banco de óvulos criopreservados: um estudo prospectivo randomizado. Jornal Brasileiro de Reproducao Assistida 2011;15(3):34-7.
    1. Figueira R, Paes D, Setti A, Iaconelli A, Borges E. Relevance of assisted hatching in an oocyte donation programme using egg cryobanking: a prospective randomised study. European Journal of Obstetrics & Gynecology and Reproductive Biology 2012;164(1):48-51. - PubMed
Frydman 2006 {published data only}
    1. Frydman N, Madoux S, Hesters L, Duvernoy C, Feyereisen E, Le Du A, et al. A randomised double-blind controlled study on the efficacy of laser zona pellucida thinning on live birth rates in cases of advanced female age. Human Reproduction 2006;21(8):2131-5. - PubMed
Gabrielsen 2004 {published data only}
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Grace 2007 {published data only}
    1. Grace J, Bolton V, Braude P, Khalaf Y. Assisted hatching is more effective when embryo quality was optimal in previous failed IVF/ICSI cycles. Journal of Obstetrics and Gynaecology 2007;27(1):56-60. [PMID: ] - PubMed
Hershlag 1999 {published data only}
    1. Hershlag A, Paine T, Cooper GW, Scholl GM, Rawlinson K, Kvapil G. Monozygotic twinning associated with mechanical assisted hatching. Fertility & Sterility 1999;71(1):144-6. - PubMed
Hiraoka 2009 {published data only}
    1. Hiraoka K, Hiraoka K, Horiuchi T, Kusuda T, Okano S, Kinutani M, et al. Impact of the size of zona pellucida thinning area on vitrified-warmed cleavage-stage embryo transfers: a prospective, randomized study. Journal of Assisted Reproduction and Genetics 2009;26(9-10):515-21. [PMID: ] - PMC - PubMed
Hur 2011 {published data only}
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Huttelova 1999 {published data only}
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Kanyo 2016 {published data only}
    1. Kanyo K, Zeke J, Kriston, R, Szücs Z, Cseh S, Somoskoi B, Konc J. The impact of laser-assisted hatching on the outcome of frozen human embryo transfer cycles. Zygote 2016;24(5):742-7. - PubMed
Kirienko 2019 {published data only}
    1. Kirienko K, Apryshko V, Naumova A, Kharitonova M, Klepukov A, Bolt A, et al. Mechanical zona pellucida removal of vitrified-warmed human blastocysts does not affect the clinical outcome. RBMO 2019;39(5):745-9. - PubMed
Komarovsky 2002 {published data only}
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Komarovsky 2003 {published data only}
    1. Komarovsky D, Bern O, Kasterstein E, Strassburger D, Raziel A, Friedler S, et al. A prospective randomized comparison between laser and chemically-assisted hatching in thawed embryo transfers. Human Reproduction 2003;18 Suppl 1:77.
Le 2018 {published data only}
    1. Le MT, Nguyen TTA, Nguyen TTT, Nguyen VT, Le DD, Nguyen VQH, et al. Thinning and drilling laser-assisted hatching in thawed embryo transfer: a randomized controlled trial. Clinical and Experimental Reproductive Medicine 2018;45(3):129-34. - PMC - PubMed
Lee 1999 {published data only}
    1. Lee JE, Lee DR, Paik HR, Shim HN, Cho JH, Roh SI, et al. Biochemical assisted hatching (BAH) increased the implantation and pregnancy rate in human cryopreserved embryo transfer [abstract]. Fertility & Sterility 1999;72(3 Suppl 1):S4-S5.
Levron 2003 {published data only}
    1. Levron J, Ferber Meiri B, Bider D, Shulman A, Levin T, Shporn E. A prospective randomized study comparing laser and tyrode's medicated methods of assisted hatching. Fertility & Sterility 2003;80 Suppl 3:S202.
Lu 2016 {published data only}
    1. Lu X-M, Xu C, Wang L, Sun N-X, Zhang Q, Guan P-F, et al. Effect of laser-assisted hatching on outcome of frozen-thawed embryo transfer for patients with previous repeated implantation failure. Academic Journal of Second Military Medical University 2016;37(1):106-10.
Lu 2019 {published data only}
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Ma 2007 {published data only}
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Magli 1998 {published and unpublished data}
    1. Magli MC, Gianaroli L, Ferraretti AP, Fortini D, Aicardi G, Montanaro N. Rescue of implantation potential in embryos with poor prognosis by assisted zona hatching. Human Reproduction 1998;13(5):1331-5. - PubMed
Mahadevan 1998 {published data only}
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Mansour 2000 {published data only}
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Meldrum 1998 {published data only}
    1. Meldrum DR, Wisot A, Yee B, Garzo G, Yeo L, Hamilton F. Assisted hatching reduces the age-related decline in IVF outcome in women younger than age 43 without increasing miscarriage or monozygotic twinning. Journal of Assisted Reproduction and Genetics 1998;15:418-21. - PMC - PubMed
Montag 1999 {published data only}
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Nadir 2005 {published data only}
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Nagy 2003 {published data only}
    1. Nagy ZP, Toledo A, Mitchell Leef D, Elsner C, Massey J, Kort H. A prospective randomized study to evaluate the effect of laser micro-hole drilling of zona pellucida prior to ICSI on implantation and pregnancy results. Human Reproduction 2003;18 Suppl 1:60-1.
Nakayama 1998 {published data only}
    1. Nakayama T, Fujiwara H, Tastumi K, Fujita K, Higuchi T, Mori T. A new assisted hatching technique using a piezo-micromanipulator. Fertility & Sterility 1998;69(4):784-8. - PubMed
Nakayama 1999 {published data only}
    1. Nakayama T, Fujiwara H, Yamada S, Tastumi K, Honda T, Fujii S. Clinical application of a new assisted hatching method using piezo-micromanipulator for morphologically low-quality embryos in poor-prognosis infertile patients. Fertility & Sterility 1999;71(6):1014-8. - PubMed
NCT02124291 {unpublished data only}
    1. NCT02124291. Effect of assisted hatching on vitrified embryo transfer clinical outcome (VitHatSZMC). http://apps.who.int/trialsearch/Trial2.aspx?TrialID=NCT02124291 (registered 23 April 2014).
Ng 2008 {published data only}
    1. Ng EH, Lau EY, Yeung WS, Cheung TM, Tang OS, Ho PC. Randomized double-blind comparison of laser zona pellucida thinning and breaching in frozen-thawed embryo transfer at the cleavage stage. Fertility & Sterility 2008;89(5):1147-53. [PMID: ] - PubMed
Obradors 2012 {published data only}
    1. Obradors A, Durban M, Pujol A, Vassena R, Coll O, Vernaeve V. Assisted hatching does not improve implantation rates when key factors are controlled for: time to stop using it? Fertility & Sterility 2013;98(3 Suppl 1):S57. [conference abstract]
Obruca 1994 {published data only}
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Peterson 2006 {published data only}
    1. Peterson C, Mauri A, Baruffi R, Oliveira J, Felipe V, Massaro F, et al. Laser-assisted hatching of cryopreserved-thawed embryos by thinning one quarter of the zona. Reproductive BioMedicine Online 2006;13(5):668-75. - PubMed
Ren 2013 {published data only}
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Ringler 1999 {published data only}
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Schoolcraft 1994 {published data only}
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Shahin 2003 {published data only}
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Sifer 2005 {unpublished data only}
    1. Sifer C, Sellami A, Martin-Pont B, Bottero J, Porcher R, Poncelet C, et al. A prospective randomised study to assess the benefit of zona pellucida partial digestion prior to frozen-thawed embryo transfers. In: ESHRE Copenhagen - oral abstract. 2005. - PubMed
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Szell 1998 {published data only}
    1. Szell AZ, Antaran JM, Chetkowski RJ. Pregnancy and implantation rates from the transfer of human embryos cultured in P1 or human tubal fluid medium and transferred with or without assisted hatching. Fertility & Sterility 1998;70:S495.
Tao 1997 {published data only}
    1. Tao J, Tamis R. Application of assisted hatching for 2-day-old, frozen-thawed embryo transfer in a poor prognosis population. Journal of Assisted Reproduction and Genetics 1997;14(2):128-30. - PMC - PubMed
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Urman 2002 {published data only}
    1. Urman B, Balaban B, Alatas C, Aksoy S, Mumcu A, Isiklas A. Zona-intact versus zona-free blastocyst transfer: a prospective randomised study. Fertility & Sterility 2002;70(3 Suppl 1):S238. - PubMed
Valojerdi 2008 {published data only}
    1. Valojerdi MR, Eftekhari-Yazdi P, Karimian L, Ashtiani SK. Effect on laser zona pellucida opening on clinical outcome of assisted reproduction technology in patients with advanced female age, recurrent implantation failure, or frozen-thawed embryos. Fertility & Sterility 2008;90(1):84-91. - PubMed
Yano 2007 {published data only}
    1. Yano K, Yano C, Kubo T, Ohashi I, Maeda N, Fukaya T. Chemical zona pellucida thinning with acidified Tyrode's solution: comparison between partial and circumferential techniques. Journal of Assisted Reproduction and Genetics 2007;24(10):471-5. [PMID: ] - PMC - PubMed
Zech 1998 {published data only}
    1. Zech H, Stecher A, Vanderzwalmen P, Murach KF. Investigation of the usefulness of laser-assisted hatching for women of ages above and below forty years [abstract]. Fertility & Sterility 1998;70(3 Suppl 1):S428.
Zhang 2009 {published data only}
    1. Zhang XJ, Yang YZ, Lv Q, Min LH, Li XL, Bai P. Effect of the size of zona pellucida thinning by laser assisted hatching on clinical outcome of human frozen-thawed embryo transfers. Cryo Letters 2009;30(6):455-61. [PMID: ] - PubMed

References to studies awaiting assessment

Elnahas A 2018 {published data only (unpublished sought but not used)}
    1. Elnahas A, Elnahas T, Azmy O, Elnoury A, Abdelhalim A, Aboelghar M, et al. The use of laser assisted hatching of frozen/ thawed embryos versus laser assisted hatching of fresh embryos in human intracytoplasmic sperm injection. Journal of Obstetrics and Gynaecology 2018;38(5):729. - PubMed

References to ongoing studies

NCT02752568 {unpublished data only}
    1. NCT02752568. Assisted hatching versus endometrial scratch in recurrent Implantation failure. http://apps.who.int/trialsearch/Trial2.aspx?TrialID=NCT02752568 (fist received 27 April 2016).
NCT03623659 {unpublished data only}
    1. NCT03623659. Does partial zona pellucida removal from vitrified-warmed human blastocysts improve delivery rate in IVF? A multicentric RCT on laser assisted hatching. clinicaltrials.gov/ct2/show/NCT03623659 (first received 9 August 2018).
NCT03810157 {unpublished data only}
    1. NCT03810157. Does laser-assisted hatching (LAH) improve the pregnancy outcomes in humans? clinicaltrials.gov/ct2/show/NCT03810157 (first received 18 January 2019).
NCT03833869 {unpublished data only}
    1. NCT03833869. The effect of assisted hatching on implantation rate in frozen blastocyst transfer - a prospective randomized controlled study. clinicaltrials.gov/ct2/show/NCT03833869 (first received 7 February 2019).
NTR3387 {unpublished data only}
    1. NTR3387. A multicentre randomized controlled trial on the efficacy of laser assisted hatching in poor prognosis patients undergoing IVF or ICSI: the AHA trial. http://apps.who.int/trialsearch/Trial2.aspx?TrialID=NTR3387 (registered 6 April 2012).

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References to other published versions of this review

Carney 2012
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