The Embryo That Should Not Be Transferred
A 38-year-old woman has one blastocyst after a cycle in which preimplantation genetic testing for aneuploidy (PGT-A) was performed. The report is inconclusive because of low DNA amplification, and the embryo is graded 3BB. The patient is anxious to proceed and asks for transfer of the untested embryo. Meanwhile, the laboratory discovers that the biopsy was taken from a region with visible fragmentation, which may explain the failed amplification. The clinic's policy states that inconclusive PGT-A results require counseling before any transfer decision.
1. What are the ethical and regulatory considerations in proceeding with transfer of an embryo with an inconclusive PGT-A result?
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An inconclusive result is not a normal result; it conveys no reassurance about chromosomal status. Transferring such an embryo is permissible only after informed consent that explains the uncertainty, the residual risk of aneuploidy, and the alternatives (repeat biopsy if feasible, or transfer without testing). The clinic's policy requiring counseling exists to ensure the patient understands that a failed amplification is a technical limitation, not evidence of abnormality.
The patient's autonomy is central, but so is non-maleficence: the clinician must not present the embryo as tested and normal. Documentation of the counseling, the patient's decision, and the reasoning is essential. The fragmented biopsy site should be noted as a probable technical cause, and the laboratory should review biopsy technique to reduce recurrence.
2. How should the laboratory address the biopsy quality issue, and what would you recommend for future cycles?
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The laboratory should review the biopsy procedure: the number of cells removed, the biopsy location relative to fragmentation, and the handling and amplification protocol. Low amplification can result from too few cells, degraded DNA, or inhibitors. A corrective action plan should include avoiding heavily fragmented regions, confirming cell number before tubing, and monitoring amplification failure rates as a quality indicator.
For future cycles, the patient should be counseled that PGT-A is optional and that its benefit is greatest when it reduces transfer of aneuploid embryos; it does not guarantee a euploid result. If the amplification failure rate is elevated, a validation review and staff retraining are warranted before offering PGT-A again.