Why did my euploid embryo fail?

A euploid embryo failing to implant is common, and it does not mean something is wrong with you or that the testing was pointless. Even a chromosomally normal embryo has a substantial chance of not implanting in any single transfer. Implantation depends on far more than chromosome count. Possible contributors: Embryo factors beyond chromosome number — the biopsy tests a few placental-lineage cells, and cannot assess overall developmental competence. Uterine factors: polyps, fibroids affecting the cavity, adhesions, or chronic inflammation of the lining. Direct assessment by hysteroscopy is the highest-yield investigation if this has happened repeatedly. Endometrial preparation, particularly luteal support adequacy in programmed cycles, which is a recognised and correctable cause. Transfer technique. Factors that are simply not yet understood, which account for a meaningful share. What is worth doing after one failure: a detailed review of the cycle rather than a battery of new tests. Ask about embryo development, lining thickness and pattern, and the preparation protocol used. What is worth doing after two or three: hysteroscopy to examine the cavity directly. What is not supported: endometrial receptivity testing, which the UK regulator rates red — no evidence it improves live births, with one study finding lower live birth rates after its use following a failed transfer. Immunological testing and treatment, and inherited thrombophilia screening, are also not supported. One failed euploid transfer is not a pattern. Ask what the realistic cumulative chance is across the embryos you have.