Hormone Replacement Therapy for Donor Embryo Transfer
Standard HRT-FET Protocol
- The American Society for Reproductive Medicine recommends continuing Progynova 6mg daily for at least 8-10 more days (until day 12-14 of the cycle) before initiating progesterone, regardless of the current endometrial thickness of 9.4mm 1
- The protocol requires continuing Progynova 6mg daily for a total of 12-14 days minimum before starting progesterone, as the timing of estrogen exposure duration is more critical than achieving a specific thickness 1
Critical Monitoring Before Progesterone Initiation
- A transvaginal ultrasound should be performed on day 12-14 to confirm endometrial thickness remains ≥7-8mm, trilaminar endometrial pattern is present, and any ovarian cysts are stable 1, 2
Progesterone Initiation Protocol
- Once adequate endometrial preparation is confirmed, progesterone 800mg vaginal daily should be started, and blastocyst transfer should be scheduled for 117-120 hours after the first progesterone dose 1
Mandatory Single Embryo Transfer
- The European Society of Human Reproduction and Embryology (ESHRE) guidelines mandate elective single embryo transfer (eSET) for all donated embryo transfers, regardless of endometrial thickness, presence of mild adenomyosis, or previous failed cycles 2, 3, 4
- Double embryo transfer increases multiple pregnancy risk 30-fold, with substantially elevated risks of pre-eclampsia, gestational diabetes, emergency cesarean section, preterm birth, and neonatal complications 2, 4