UTM is an optional solution that is used exclusively at the time of embryo transfer. The selected embryo is bathed in UTM before being deposited back into the uterus with a small volume of the medium.

UTM contains a molecule known as ‘hyaluronan’. Hyaluronan is naturally occurring within the body, and its synthesis within the uterus is known to peak at the time of implantation. Hyaluronan gives UTM greater viscosity than conventional culture media and acts like a bridge between the embryo and the uterine surface. The increased cell adhesion facilitated by UTM may assist in the early stages of embryo attachment to the uterine lining, potentially enhancing the chance of achieving implantation and pregnancy in some patients.