Advances in prenatal diagnosis including improvements in ultrasonography have revealed the natural history of fetal sacrococcygeal teratomas, and this natural history differs substantially from that for postnatally diagnosed sacrococcygeal teratoma. A fetal sacrococcygeal teratoma may lead to perinatal morbidity and mortality by a variety of mechanisms. Adverse clinical sequelae of a sacrococcygeal teratoma can be prevented by accurate prenatal assessment and appropriate obstetrical and perinatal management. Development of fetal hydrops and/or placentomegaly predicts fetal demise. Fetal surgical intervention has proven successful in highly selected cases.