In vitro maturation (IVM) , like stimulated normal IVF, involves the retrieval of eggs from a woman's ovaries, followed by fertilization in a lab, and then implantation of one or more fertilized embryos back into the woman's uterus.

The crucial difference is the state of the eggs at retrieval: With IVF, the eggs are matured inside the ovaries, while in IVM collected immature eggs are placed in a petri dish and exposed to a combination of luteinizing hormones and follicle stimulating hormones.