Trophectoderm biopsy for preimplantation genetic test and technical tips: A review

BACKGROUND: Recently, the Japan Society of Obstetrics and Gynecology initiated a clinical study of preimplantation genetic test for aneuploidy. There will be a great need for a standardized embryo biopsy technique in Japan. However, the gold standard trophectoderm (TE) biopsy procedure has not been established, and this review outlines the clinical use of TE biopsy. METHODS: Based on literature, the method and associated techniques for TE biopsy, a dissection method of TE cells from blastocysts, were investigated. MAIN FINDINGS: Two TE biopsy methods are used, namely assisted hatching (herniating) and non‐assisted hatching (direct suction); however, it is not clear which of these methods is superior. It is critical to understand whether the flicking or pulling method is beneficial. CONCLUSION: Non‐assisted hatching biopsy method may cause blastocyst collapse with a higher probability, and it may extend the biopsy time. The biopsy procedure should be performed within 3 minutes, and thus direct TE suction may have greater disadvantages. It is a fact that pulling method of TE dissection with laser pulse is simple; however, excess laser shots may induce a higher frequency of mosaicism. It is important to understand that each technique of TE biopsy has benefits and disadvantages.