Neonatal thrombosis with anticardiolipin antibody in baby and mother

The anticardiolipin antibody is associated with increased risk of thrombosis, which is manifested with various clinical presentations, including vascular thrombosis, recurrent fetal wastage, and neurologic defects. We report a case of neonatal thrombosis occurring in the renal vein and inferior vena cava associated with moderate positive anticardiolipin antibody titer in the baby while the maternal serum showed even stronger anticardiolipin antibody of immunoglobulin G class. Subsequent follow-up over the 4 months postpartum period showed a disappearance of the antibody in the baby, whereas the mother's antibody persisted. This case illustrates the fact that the maternal anticardiolipin antibody can be transferred to the fetus and may be a risk factor for thrombosis in the neonates. Anticardiolipin antibody syndrome should be considered in the differential diagnosis of neonatal thrombosis.