Frozen embryo transfer
From the fertility booklet The A.R.T. of Fertility:
A patient guide by the Fertility & IVF Center of Miami
During a frozen embryo transfer, the embryos are thawed and transferred into the uterus. In order for embryos to be able to implant, they must be transferred into the uterus during a specific time frame during which the uterus is receptive. An artificial cycle is created to condition the uterus and transfer the embryos at the most optimal time.
Patients start daily injections of Lupron 1 week before their expected period to down-regulate the ovaries.
Once the menses begins, a baseline ultrasound is performed to assess for any ovarian cysts or any other abnormality; a blood test to measure the hormone Estradiol is also taken to verify down-regulation. If the baseline assessment is within normal, the patient begins a regime of skin patches containing the hormone Estradiol. In some cases, oral pills called Estrace are used as an alternative to patches. Estradiol builds the lining inside the uterus to receive an embryo. On the 13th day of the patch protocol, the patient attends the office for an ultrasound to assess that the lining has reached an optimal thickness, and blood levels of Estradiol are appropriate. After this assessment, the patient commences daily injections of Progesterone and stops Lupron injections on a designated day (usually the 15th day of patches). The embryos are then thawed on the appropriate day according to their developmental stage. The transfer then takes place on the corresponding day. A pregnancy blood test is performed in the same fashion as a regular IVF cycle. Continued hormonal support with patches and injections are essential during this cycle of treatment. When a patient becomes pregnant, hormonal support continues throughout the 10th to the 12th week of pregnancy.