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, I2=0%), clinical pregnancy (RR 1.00, 95% CI 0.83 to 1.19, 8 RCTs, n=870, I2=22%), implantation (RR 1.07, 95% CI 0.83 to 1.39, 4 RCTs, n=1359, I2=0%), miscarriage (RR 1.13, 95% CI 0.66 to 1.94, 2 RCTs, n=116, I2=0%) and multiple pregnancy (RR 0.89, 95% CI 0.31 to 2.52, 1 RCT, n=97, I2=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.
Keywords: advanced maternal age; assisted hatching; frozen-thawed embryo transfer; in vitro fertilization.