Sacrococcygeal teratoma is the most common tumor in infants. About 80% of these tumors are types 1 and 2, and are unlikely to cause metastases whose incidence is 10% in the neonatal period, against nearly 100% at the age of 3 years. These tumors can acquire huge and contain large proportions depriving blood flows to the developing fetus, the tumor hypervascularity generates a hyperdynamic state in the fetus, and that as the tumor grows, it increases its flow to behave as a short circuit and to be similar to that of the lower limbs of the fetus, increasing venous return and cardiac output, heart failure causing fetal and maternal eclampsia.