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

Comparison of Live Birth Rate (> 24 Weeks) in Natural Cycle (NC) Single Euploid Frozen Embryo Transfers (FET) With Versus Without Luteal Phase Support (LPS)

To evaluate whether single euploid embryo transfer in NC without routinely administered LPS is non-inferior to NC with routinely administered LPS.

In case the study will show that the live birth rate in single euploid NC frozen embryo transfer cycles without LPS is not inferior to NC cycles with LPS, treatment can be simplified, and participants comfort can be increased.

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….)