Pericardial cystic mass with fetal tachycardia

A pericardial cystic mass is a rare congenital anomaly and may be mistaken for other pericardial and pleural masses. A 31-year-old pregnant woman at 38 weeks of gestation presented with fetal pericardial cyst and fetal tachycardia, which were confirmed by transthoracal echocardiography after delivery. Tachycardia did not persist after delivery. The case is being followed up without any clinical problems at the pediatric cardiology clinic.