Comparison of Live Birth Rate in Natural Cycle Single Euploid FET Versus Without Luteal Phase Support

Inclusion Criteria: * Age: 18 to 40 years * Regular ovulatory cycles * Availability of at least one euploid embryo after Trophectoderm biopsy for PGT-A on day 5 or day 6 * Detection of ovulation by P4 rise \> 1.0 ng/ml after LH surge * P4 value of at least 5 ng/ml on day 4 after ovulation Exclusion Criteria: * History of repeated pre-menstrual spotting * Factors affecting the implantation through anatomical changes of the uterus / ovaries or the tubes (adenomyosis, Asherman syndrome, endometriosis, uterine fibroids / polyps, isthmocele with intracavitary fluid presence, hydrosalpinx….)