Trophectoderm biopsy is the most common method of embryo biopsy for pre-implantation genetic screening. Since trophectoderm cells are extra-embryonic tissue, they do not become part of the fetus but do become part of supporting structures, such as the placenta and membranes. Trophectoderm biopsy takes place at the 16-32 cell “blastocyst” stage of development, as the trophectoderm is beginning to herniate through the zona pellucida. Instead of removing individual blastomeres, several trophectoderm cells are removed.
Laser-asssisted Trophectoderm Biopsy Process