PGT-SR (reciprocal translocation) using trophectoderm sampling and next-generation sequencing: insights from a...

Area of Science:

• Reproductive Medicine
• Clinical Genetics
• Embryology

Background:

• Reciprocal translocations in couples can lead to chromosomally unbalanced pregnancies.
• Preimplantation genetic testing for structural rearrangements (PGT-SR) aims to reduce miscarriage risk.
• Next-generation sequencing (NGS) and trophectoderm biopsy are current PGT-SR techniques.

Purpose of the Study:

• To simulate and assess costs and benefits of PGT-SR reporting strategies for reciprocal translocations.
• To compare reporting all chromosomes versus only translocation-involved chromosomes.
• To evaluate impact on pregnancy outcomes, costs, and cycle time.

Main Methods:

• A simulation model for women under 35 undergoing single embryo transfer after NGS trophectoderm biopsy.
• Evaluated three reporting strategies: targeted (translocation only), exclusion (all abnormal), and ranking (prioritizing uncertain embryos).
• Assessed live birth rates, miscarriage, biochemical pregnancy, costs, and time to cycle completion.

Main Results:

• Ranking all chromosomes was cost-effective, avoiding adverse pregnancies without compromising live birth chances.
• Targeted reporting was less effective in avoiding adverse pregnancies compared to ranked reporting.
• Exclusion strategies resulted in fewer live births; ranked and exclusion strategies marginally reduced cost and time.

Conclusions:

• Targeted reporting (translocation chromosomes only) is preferred for maximizing live birth rates in PGT-SR.
• Ranking and excluding embryos with unrelated chromosomal abnormalities may be detrimental to live birth success.
• Individualized genetic counseling is crucial for couples to weigh risks and benefits of PGT-SR strategies.