Assisted hatching - A meta-analysis of randomized controlled trials

Purpose: To conduct a meta-analysis of randomized controlled trials (RCTs) on assisted hatching. Methods: One hundred sixty-five studies were retrieved from the literature, but only 13 of them fitted our selection criteria. The meta-analysis was conducted using the RevMan software with the Peto-modified Mantel - Haenszel method. Results: Assisted hatching increases the pregnancy [OR (+/-95% CI) = 2.51 (1.91 - 3.29)], implantation [OR (+/-95% CI) = 2.38 (1.87 - 3.03)], and ongoing pregnancy rates [OR (+/-95% CI) = 2.65 (1.85 - 3.79)] significantly in poor prognosis patients undergoing IVF or ICSI. For patients with repeated IVF failures, the OR (+/-95% CI) were 2.84 (1.99 - 4.06) for pregnancy, 2.53 (1.85 - 3.47) for implantation, and 3.51 (2.12 - 5.82) for ongoing pregnancy rates, in favor of assisted hatching. Conclusions: Assisted hatching increases the pregnancy, implantation, and ongoing pregnancy rates significantly in patients with a poor prognosis undergoing IVF or ICSI, particularly those with repeated failures.