Table 1 Specific information characteristics
From: Two laser-assisted hatching methods of embryos in ART: a systematic review and meta-analysis
Study/ Country | Method for allocation | Laser assisted hatching system | Inclusion criteria | Exclusion criteria | Age | Times of AH | Embryo (fresh or frozen) | Participants D-LAH/T-LAH |
|---|---|---|---|---|---|---|---|---|
E.Mantoudis et al. 2001 (United Kingdom) [26] | non-RCT | Fertilase™, Medical Technologies, Montreux SA, Switzerland | (i) Patients having frozen embryo replacement (ii) Two previous IVF or ICSI failed cycles (iii) Patients requiring high dose gonadotrophins, more than 50 ampoules, or a dose of 5 or more ampoules per day | Not stated |  > 38 | Day 3 | Fresh | 77/245 |
TS Ghobara et al. 2006 (United Kingdom) [27] | non-RCT | MMT Medical Technologies, Montreux SA, Switzerland | (i) The woman’s age was 38 years or more (ii) The couple had had three or more unsuccessful IVF/ICSI cycles | Not stated | 27–48 | Not stated | Fresh | 312/592 |
Ernest Hung Yu Ng et al. 2008 (China) [28] | RCT | Zona Knife; SL Microtest GmbH, Jena,Germany | Patients had at least two frozen embryos available for transfer | (i) More than three stimulated IVF cycles (ii) Only one frozen embryo before thawing (iii) Frozen embryos replaced in stimulated IVF cycles (iv) Recipients of donor oocytes (v) Lysis of all frozen embryos on thawing (vi) Frozen embryos with ZP thickness of < 13 mm | Not stated | Cleavage stage | Frozen | 90/90 |
B. Ma et al. 2014 (China) [16] | RCT | Lykos laser: Hamilton Thorne, Beverly, MA, USA | Patients had at least three previous implantation failures in fresh day-3 embryo transfers | Not stated |  < 37 | Day 3 | Fresh | 52/49 |
Minh Tam Le et al. 2018 (Vietnamese) [29] | RCT | Saturn 5 Active; BioMedical Instruments, Zoellnitz, Germany | (i)A maximum of three previous failed IVF-ET procedures (ii)Undergoing FET | Not stated | 22–47 | Day 3 | Frozen | 85/86 |
Jung-Woo Lee et al. 2019 (Korea) [24] | non-RCT | Hamilton Thorne Instruments Biosciences, Beverly,MA, USA | (i)Patients had a least two episodes of implantation failure (ii)Patients had an endometrial thickness ≥ 8 mm on the day of embryos transfer | Patients who underwent oocyte donation, oocyte activation, or genetic diagnosis, as well as those who used surrogate mother |  < 38,  ≥ 38 | Cleavage stage | Fresh | 218/191 |
Chengjun Liu et al. 2020 (China) [23] | non-RCT | HAMILTON THORNE, ZILOS-tk, USA | (i) Frozen blastocyst transfer with LAH (ii) The first frozen embryo transfer (FET) cycle and no fresh embryo transfer cycle in our center (iii) Normal karyotype of both husband and wife (iv) Endometrial thickness greater than 7 mm on the day of FET | (i) Female with endometriosis or adenomyosis (ii) Unexplained infertility of the couples | 31.1 ± 4.2 | Day 3 | Frozen | 864/254 |
Yujiang Wang et al. 2022 (China) [12] | non-RCT | ZILOS-tk®, Hamilton-Thorne Instruments Biosciences | (i) Patients had undergone Day 4 frozen-thawed embryo transfer (ii) Patients had a maximum of four previous failed IVF-ET procedures (iii) All embryo transfers had been performed using embryos at the morula or cleavage-stage (blastomeres continued to grow after thawing) | Not stated | 22–47 | Day 4 | Frozen | 694/716 |
Ling Zhang et al. 2022 (China) [30] | RCT | MTG Medical Technology, Altdorf, Germany | (i) Couples with more than 2 highly fragmented day-3 cleavage embryos (specified as embryos originating from 2PN zygote, with fragment rate > 25% and at least 4 blastomeres) (ii) Receiving extended in vitro culture | (i) Abnormal karyotypes of any partner (ii) Embryos originating from assisted oocyte activating or in vitro maturation procedure (iii) Familial infertility of any partner |  < 40 | Day 3 | Fresh | 13/16 |