Laser-assisted hatching improves clinical outcomes of vitrified–warmed blastocysts developed from low-grade cleavage-stage embryos: a prospective randomized study

Abstract

The aim of this study was to evaluate the effects of quarter zona-pellucida (ZP) opening by laser-assisted hatching (QLAH) on the clinical outcomes following transfer of vitrified-warmed blastocysts developed from low-grade cleavage-stage embryos in patients with all high-grade and fair-grade cleavage-stage embryos transferred without achieving pregnancy. Patients were randomized into two groups: QLAH (n=101) and control (n=102). The implantation and clinical pregnancy rates were significantly higher in the QLAH group compared with the control group (P=0.021 and P=0.034, respectively). The live birth rate of the QLAH group was also higher, although not significantly. When the clinical outcomes according to the day of blastocyst vitrification were compared between the groups, the implantation, clinical pregnancy and live birth rates of the QLAH group were significantly higher (P<0.05) than those of the control group for day 6 blastocysts, but not for day 5 or day 5/day 6 blastocysts. These results suggest that QLAH improves the clinical outcomes of vitrified-warmed blastocysts, especially of day 6 vitrified blastocysts, developed from low-grade cleavage-stage embryos.

Effect of assisted hatching on pregnancy outcomes: a systematic review and meta-analysis of randomized controlled trials

“…These studies were published between 1992 and 2014. Of these studies, eight studies were conducted in the USA 5 6 7 8 9 10 11 12 , five studies each in China 13 14 15 16 17 and Turkey 18 19 20 21 22 , three studies each in Brail 23 24 25 and Italy 26 27 28 , two studies each in Iran 29 30 and Israel 31 32 , and one study each in Canada 33 , Germany 34 , Egypt 35 , Switzerland 36 , the Czech Republic 37 , Japan 38 , Australia 39 , and Belgium 40 . Women received either in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) were observed in fourteen, nine, and seven studies, respectively.…”

Laser technology in the ART laboratory: a narrative review

“…A prospective RCT found that quarter LAH did not improve the implantation rate in vitrified-warmed/frozen-thawed embryo transfer cycles when compared with the control group, reporting a similar implantation rate (13.3% versus 15.6%), ongoing implantation rate (10.5% versus 13.5%) and live birth rate (10.5% versus 13.3%) per embryo transferred (Debrock et al, 2011). Conversely, Wan and colleagues found that quarter LAH could improve the clinical outcomes of vitrified-warmed blastocysts, especially for day-6 blastocysts that developed from low-grade cleavage-stage embryos (Wan et al, 2014). In addition, when compared with 335 control cycles, a higher implantation rate, clinical pregnancy rate and live birth rate were observed in 480 cryopreserved embryo transfer cycles in which LAH was carried out on day-3 cleavage-stage embryos (Zhou et al, 2014).…”

“…Second, assisted hatching may promote the initiation of implantation as embryos with an artificial gap created in the zona pellucida can make contact with the endometrium earlier than embryos with an intact zona pelluzida (Malter and Cohen, 1989). Third, the artificial gap formed via assisted hatching may serve as a channel for the exchange of metabolites and growth factors between the embryo and the endometrium prior to hatching, which subsequently facilitates implantation (Hammadeh et al, 2011;Wan et al, 2014).…”

Comparative secretome profile analysis of cultured immortalized human endometrial stromal cells supplemented with implanted versus nonimplanted blastocyst‐conditioned medium: A preliminary analysis

“…Embryo quality was evaluated every day according to previously reported criteria. 16 On day 3 after fertilization, the embryos were transferred from the first-stage cleavage medium to a 25-μL drop of second-stage blastocyst medium for individual extended culture. Blastocyst morphology was observed on days 5 and the blastocyst quality was assessed using the Gardner and Schoolcraft scoring standard.…”