Difficulty of fetal monitoring in a fetus with intracardiac tumors.

Fetal intracardiac tumors are rare but, when present, are a common cause of poor or uninterpretable fetal heart tracings due to fetal arrhythmias. The most frequently encountered tumor, the rhabdomyoma, is associated with tuberous sclerosis. We present a case demonstrating this difficulty of fetal monitoring in a fetus with an arrhythmia later found to be due to multicentric intracardiac rhabdomyomas. The appropriate evaluation and management of such fetal heart tracings are discussed.