Since the advent of preimplantation genetic testing for aneuploidy (PGT-A) in the 1990s, substantial changes in test methodology and technology now allow the detection and reporting of intermediate chromosome copy number (commonly referred to as mosaicism) for aneuploidy in a trophectoderm biopsy sample. Clinicians are grappling with how to interpret such findings and how to counsel patients about embryo transfer decision-making. This document reviews the available literature and outlines the various issues surrounding the reporting of intermediate copy number and consideration of storage or transfer of blastocysts with intermediate copy number results. This document does not endorse, nor does it suggest that PGT-A is appropriate for all cases of in vitro fertilization.

自从 1990 年代出现非整倍体植入前基因检测 (PGT-A) 以来，测试方法和技术的重大变化现在允许检测和报告滋养外胚层活检样本中非整倍体的中间染色体拷贝数（通常称为嵌合） . 临床医生正在努力解决如何解释这些发现以及如何就胚胎移植决策向患者提供咨询。本文件回顾了现有文献并概述了围绕中间拷贝数报告的各种问题，以及考虑储存或转移具有中间拷贝数结果的囊胚。本文件不认可，也不建议 PGT-A 适用于所有体外受精情况。