Transplacental Sirolimus for Reversal of Fetal Heart Failure due to Fetal Cardiac Rhabdomyoma: Fetal and Maternal Considerations

Background:Rhabdomyoma is the most common cardiactumor in fetal life. It has frequent association with tuberoussclerosis complex and may lead to heart failure, a potentiallyfatal condition. The use of transplacental sirolimus, amammalian target of rapamycin inhibitor, has emerged as anovel treatment in symptomatic fetal rhabdomyomas;however, there are only few cases described.CasePresentation:A 37-year-old woman at 29 weeks and4 days of gestation had been diagnosed with fetal cardiactumor, adhered adjacent to the left ventricle, associated withheart dysfunction and polyhydramnios. Therapy with oralsirolimus was started, and, once serum levels were achieved,cardiac tumor reduction was observed, with progressiveresolution of cardiac dysfunction. However, maternal hy-pertriglyceridemia was developed as a side effect, a rarelydiscussed theme on previous articles, and was successfullycontrolled with dose reduction. The patient delivered a maleinfant at 38 weeks and 2 days of pregnancy with no need ofany resuscitation maneuver.Conclusion:Transplacentaltreatment with sirolimus is a promising therapeutic optionto treat symptomatic fetal rhabdomyomas, but more dataare demanded to determine its efficacy and safety duringpregnancy. A close maternal follow-up concerning triglyc-eride levels is mandatory.(c) 2025 S. Karger AG, Basel