What is the definition or description of: embryo transfer?

Embryo transfer: Embryo transfer (also et, set. Fet, etc) refers to placing one or more human embryo(s) (multi-cell or blastocyst) into the uterus of a woman trying to become pregnant. Et is the final step in an ivf cycle, and is done in some other circumstances as well. It is extremely safe, mostly comfortable, and usually not technically difficult. Experts agree on its importance, but often differ on specifics.