The hormones that promote endometrial growth during the first phase of the cycle (proliferative) are estrogens. They are administered in most of the treatments that involve an embryo transfer in an additional cycle, aside from the ovarian stimulation one. In short, estrogen is administered in the following cases:
- IVF-ICSI treatments with donor eggs, with both fresh and frozen eggs/embryos
- Frozen embryo transfers (using embryos that were frozen in previous cycles)
- Embryo donation
Suggested for you: Endometrial Preparation for Implantation After IVF Embryo Transfer.