The following are required in order to transfer frozen embryos:
In the clinic: the future mother has to be prepared hormonally to receive the embryo. This simply means that she will be given estrogen using patches (or sometimes orally) so that her endometrium develops correctly. The doctor will monitor her condition with ultrasound and blood tests for 10-15 days.
In the laboratory: when the endometrium is ready, the patient’s embryos are thawed out. They are then put in culture until they fully recover and they are analyzed again. Finally, the embryos are injected into the uterus using the normal process, with a catheter, guided via ultrasound.