Assisted Hatching in Couples with Advanced Maternal Age： A Systematic Review and Meta-analysis

This systematic review aimed to evaluate the efficacy and safety of assisted hatching （AH） performed in couples with advanced maternal age. We searched for randomized controlled trials （RCTs） in electronic databases, including MEDLINE, EMBASE and CENTRAL （from inception to January 2018）; in addition, we hand-searched the reference lists of included studies and similar reviews. We included RCTs comparing AH versus no treatment （control）. The meta-analysis was performed by RevMan 5.3 software. The search retrieved 943 records and 8 RCTs were included, comprising 870 cycles （n=440 for AH, and n=430 for control）. There was no significant difference in the rates of live birth （RR 0.88, 95% CI 0.65 to 1.18, 3 RCTs, n-427,I^2=0%）, clinical pregnancy （RR 1.00, 95% CI 0.83 to 1.19, 8 RCTs, n=870, I^2=22%）, implantation （RR 1.07, 95% CI 0.83 to 1.39, 4 RCTs, n=1359, I^2=0%）, miscarriage （RR 1.13, 95% CI 0.66 to 1.94, 2 RCTs, n=116, I^2=0%） and multiple pregnancy （RR 0.89, 95% CI 0.31 to 2.52, 1 RCT, n=97,I^2=not applicable） between the treatment group and control group. No reasonable conclusions could be drawn regarding reproductive outcomes after AH in patients with advanced maternal age due to the small sample pooled in meta-analyses. Studies of high methodological quality and with adequate power are necessary to further investigate the value of AH in assisted conception of those patients.

Effect of an Improved Mechanical Method for Assisted Hatching on the in vitro Development of Mouse Embryos

Objective To evaluate the safety and efficiency of an improved shape of opening for mechanical assisted hatching （AH） on the in virto development of mouse embryos. Methods A total of 622 KM BAI mouse embryos in 2-cell-4-cell stage were randomly divided into group A, group B and control group. A new mechanical AH method by improving the shape of opening in the ZP was used in group A, and a ＂-/ ＂-shaped opening was created. A ＂＋ ＂ -shaped opening was made in group B, while no opening was made in control group. Comparisons have been made among the three groups with regard to the duration of AH, the blastocyst formation and complete hatching rate, etc. Results The duration of AH in group A （43.25 ±3.46 s） was significantly shorter than that in group B （52.81 ±4.32 s, P 〈0.05）. The blastocyst formation rate on d 5 was not significantly different among the three groups （92.27%, 93.66% and 94.92% respectively, P 〉0.05）. The complete hatching rate of blastocysts on d 6 between group A and group B was no statistical difference （94.09% vs 92.71%, P 〉0.05）, but significantly higher than that in control group （43.32%, P 〈0.001）. No significant difference in the percentage of grade 1 blastocysts was found among the three groups on d 5 （85.22%, 82.81% and 86.63% respectively, P 〉0.05）. Conclusion R could enhance the process of embryo hatching and facilitate the hatching rate of blastocysts by using the improved mechanical AH method, which is of safety and efficiency to mouse embryo in the in vitro development.