Hyaluronan-enriched Medium and Euploid Blastocyst Transfers

Inclusion Criteria: * All frozen embryo transfer (FET) cycles with euploid blastocysts biopsied and vitrified on Day 5 after PGT-A. * Rank of randomization based on embryo quality. * Only hormonal replacement theraphy (HRT) cycle regimen. * Women aged 18 years to 46 years. * Having at least 1 chromosomally normal vitrified blastocyst(s) on Day 5 available for transfer. * All sperm samples. * BMI between 18 and 35. Exclusion Criteria: * FET cycles with preimplantation genetic testing for monogenic disorders (PGT-M) and for structural rearrangements (PGT-SR). * FET cycles with mosaic / aneuploid blastocysts. * FET cycles with unknown outcome. * FET cycles with Day 6 or Day 7 biopsied blastocysts. * FET with patients' endometrium preparation with treatments other than HRT. * FET where PGT-A was performed for gender selection.