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.