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Evidence-based · Patient-friendly

The Myth of the “Perfect” Embryo

Research shows that PGT-A does not improve pregnancy or live birth rates — especially when counting all patients from the start of treatment (intention-to-treat).

Not a routine must-have Small sample ≠ whole embryo Mosaicism matters
PGT-A is an optional IVF test that checks a few cells from an embryo for chromosome count. Because it analyzes only a small sample, errors can occur in up to 25% of cases. Results may also be affected by mosaicism — a mix of normal and abnormal cells.

What Are the Limitations?

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Clinically unconvincing results

PGT-A does not lead to better pregnancy or birth rates when all patients are included from the start of treatment.

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Technical errors

Inaccurate readings may occur due to mosaicism or DNA testing errors — these can affect up to 25% of results.

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Unnecessary discarding of embryos

Embryos labeled “unsuitable” (e.g., mosaic) have resulted in healthy babies — meaning some may have been discarded unnecessarily.

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Ethical & financial issues

The test is costly, emotionally exhausting, and often presented as “essential” despite limited evidence of benefit.

Key Takeaways

  • PGT-A may not improve outcomes for many patients.
  • Small sampling can lead to significant misinterpretation.
  • Many “abnormal” embryos may still result in live births.
  • Emotional & financial costs can outweigh benefits.
25%
Potential error rate due to sampling and mosaicism reported across studies.
Good to know: a single test result should be interpreted in clinical context and discussed with your care team.
SOURCES
  1. Paulson, R. J. (2023). Preimplantation genetic testing: The great divide. Fertility and Sterility, 120(3), 408–409.
  2. Kawwass, J. F., et al. (2024). IVF add-ons and their effectiveness: A systematic review and meta-analysis. Human Reproduction, 39(2), 215–227.
  3. Gleicher, N., Barad, D. H. (2019). Preimplantation genetic testing for aneuploidy (PGT-A): Finally revealed. ResearchGate Preprint.
www.aboutivf.com · Evidence-based IVF resources

This material is for informational purposes only — always consult your doctor before making any decisions.