Fetal cardiac rhabdomyomas can cause serious complications, including intrauterine death, but there are no precise criteria for their prenatal treatment. A review of 13 studies with 15 fetuses, of which 66.6% had multiple rhabdomyomas, examined the use of mTOR inhibitors, most commonly sirolimus (86.6%) and to a lesser extent everolimus (13.3%). Prenatal treatment was indicated for progressive tumor growth causing outflow obstruction, hemodynamic problems, arrhythmias or fetal hydrops. Therapy started on average at the 30th week of pregnancy and ended around the 38th week. All cases experienced tumor shrinkage and improvement in cardiac function, although 33.3% of fetuses experienced regrowth after treatment. No fetal or neonatal deaths were reported, and no postnatal cardiac surgery was required before discharge. Based on these data, a prenatal management algorithm was designed with echocardiographic criteria for selecting suitable candidates for treatment. Prenatal therapy with mTOR inhibitors may thus improve fetal cardiac function and perinatal outcomes, but further validation in future studies is needed.