Genes, Journal Year: 2025, Volume and Issue: 16(2), P. 134 - 134
Published: Jan. 24, 2025
Trophectoderm (TE) biopsy is at present the most widely used procedure for preimplantation genetic testing (PGT). At blastocyst stage, more TE cells (five to seven) can be obtained analysis. While removing and not touching inner cell mass (ICM), less invasive. Due a natural selection happening between day 3 5, 6 or 7 of human embryo development, fewer embryos will have biopsied tested. An additional benefit, especially in view aneuploidy (PGT-A), lower level mosaicism stage. The involves two steps: laser-assisted zona pellucida (ZP) opening excision five eight from with without laser energy. Different protocols emerged over time variations regarding technique, exact moment ZP opening, method removal. ‘pulling’ excision, whereas ‘flicking’ represents mechanical approach assistance. Embryo developmental speed reaching full/expanded hatching/hatched stage dictates timing procedure, mostly on 5 post-insemination, lesser extent even 7. inclusion quality delayed blastocysts may impact sample as well clinical outcome. Intracytoplasmic sperm injection (ICSI) still preferred fertilization PGT-M (monogenic disorders) PGT-SR (structural rearrangements). However, conventional vitro (IVF) seems feasible PGT-A (aneuploidy testing). In absence (conclusive) result, re-biopsy cryopreserved possible, however, reduced outcomes. So far, neonatal outcome post-TE has so far been reassuringly documented.
Language: Английский