A multinational multi-centre, randomized, controlled non-blinded trial with participation of three fertility clinics in Denmark and one in Spain to assess the efficacy and safety of preimplantation genetic testing for aneuploidy (PGT-A) in 37-41-year-old women.

Inclusion Criteria:

• Women aged 37-41 years with a male partner, a female partner og undergoing fertility with no partner.
• Anti Müllerian Hormone (AMH) ≥6.28 pmol/L (AMH should be measured no more than one year prior to study inclusion). The optimal is to use the Elecsys® Assay. If other assays are used this should be reported to the investigator and the AMH cut-off level may appropriately be changed so that it corresponds to the cut-off used in the Elecsys® Assay.
• IVF/ICSI cycle number 1-5 (previous IVF/ICSI cycles will not count if the woman is recruited after an IVF/ICSI/FET-delivery).

Exclusion Criteria:

• PGT-SR or PGT-M.
• Testicular sperm aspiration (TESA), testicular sperm extraction (TESE), micro-TESE (or cryopreserved sperm from these procedures).
• Males with severely compromised semen quality (<1 million progressively motile sperm cells following gradient centrifugation).
• Endometriosis stage three or four.
• Women with severe thyroid disease (women can be included if they have normal thyroid levels on relevant medication).
• Severe co-morbidity; diabetes mellitus type 1 (DM1), Mb Crohn or Colitis ulcerosa, systemic lupus erythematosus (SLE), HIV, Hepatitis B/C, or dysregulated thyroid disease.
• ≥2 previous ART treatment without blastocyst formation.

Female