Does PGT-A reduce miscarriage?

Partially, and less reliably than commonly claimed. The logic is sound: most early miscarriages are caused by chromosome abnormalities, so avoiding the transfer of chromosomally abnormal embryos should reduce miscarriage. In practice the effect is smaller than the logic suggests. ASRM (2026) states that although some observational studies show a reduction in miscarriage, miscarriage still occurs in 10 to 20% of pregnancies after PGT-A. And overall, PGT-A has not been shown to significantly reduce miscarriage compared with expectant management in the setting of recurrent pregnancy loss. Why miscarriage still happens after a euploid transfer: The biopsy samples a few placental-lineage cells, which may not represent the whole embryo. Mosaicism can mean the tested cells differ from the rest. Miscarriage has causes other than chromosomes — uterine, hormonal, immune, and often unidentified. ASRM notes that women with recurrent loss actually have a higher likelihood of euploid miscarriage than women with isolated losses, and that likelihood rises with the number of losses. That last point matters if you have had several miscarriages: your losses may be less likely to be chromosomal than average, which limits what PGT-A can address. Where it is reasonable to discuss: ASRM says in women over 40 with a proven aneuploid miscarriage, PGT-A can be discussed using shared decision-making to reduce miscarriage due to aneuploidy. A euploid result reduces the risk. It does not remove it.