Two laser-assisted hatching methods of embryos in ART: a systematic review and meta-analysis

Area of Science:

• Reproductive Medicine
• Embryology
• Infertility Treatment

Background:

• Laser-assisted hatching (LAH) is crucial for embryo manipulation in assisted reproductive technology (ART).
• Two primary LAH methods, drilling (D-LAH) and thinning (T-LAH), are widely used but their comparative efficacy is unclear.
• Existing research presents limitations, necessitating a comprehensive evaluation of their impact on pregnancy outcomes.

Approach:

• A systematic meta-analysis was conducted, searching PubMed, Web of Science, and Cochrane Library until July 20, 2022.
• Included observational studies and randomized controlled trials (RCTs) comparing D-LAH and T-LAH.
• Statistical analysis utilized risk ratios (RR) with 95% confidence intervals (CI) and I-squared statistics to assess heterogeneity.

Key Points:

• Meta-analysis of 9 studies (2405 pregnancies for D-LAH, 2239 for T-LAH) found no significant difference in clinical pregnancy rates (RR=0.93, 95% CI: 0.79-1.10).
• D-LAH showed a higher incidence of singleton pregnancies (RR=2.28, 95% CI: 1.08-4.82), though with substantial heterogeneity (I²=89%).
• No significant differences were observed in implantation rates, multiple pregnancies, miscarriage, or live birth rates.

Conclusions:

• Both D-LAH and T-LAH demonstrate comparable clinical pregnancy rates in ART.
• The choice between D-LAH and T-LAH may depend on individual patient circumstances.
• High-quality RCTs are recommended to further elucidate the precise impact of these LAH techniques on ART success due to limited study numbers.