Supplementary Material for: Successful perinatal management of a large fetal intrapericardial teratoma by serial fetal echocardiogram and ex-utero intrapartum treatment

Introduction: Pericardial teratomas are rare tumors located in the pericardial space compressing the heart from the outside and usually associated with pericardial effusions. When these tumors are diagnosed in utero, there are some management challenges, including the best approach of prenatal follow-up, the ideal timing of delivery and the perinatal therapeutic strategies. The tumors although benign, tend to grow considerably prenatally, imposing increased risk of worsening pericardial effusion, compression of the heart and potentially compromising cardiac output, leading to intrauterine death.
Case Presentation: We are presenting an extremely large pericardial teratoma diagnosed at 20 weeks’ gestation that was followed serially and closely by fetal echocardiogram and ultrasound throughout the gestation. The baby was successfully delivered by EXIT-to-resection procedure because of sudden progression to fetal hydrops associated with maternal mirror syndrome. On placental-fetal circulation, the pericardial teratoma was completely resected allowing for successful maternal-fetal outcome.
Conclusion: Serial fetal echocardiogram is a key prenatal tool to evaluate fetal cardiac function in intrapericardial teratomas. EXIT procedure with intrapartum resection of large pericardial teratoma is a safe perinatal strategic option to improve the outcomes of those babies.