Umbilical vein thrombosis and maternal diabetes mellitus.

Antenatal thrombosis of the umbilical vessels is a rare phenomenon and is associated with high perinatal mortality. Chorionic vessel and perinatal renal venous thromboses occur more frequently in the offspring of diabetic mothers. Nonimmunologic hydrops fetalis is also an uncommon occurrence, the cause of which often remains obscure. A unique case of nonimmunologic hydrops fetalis occurring in the fetus of a gestational diabetic and associated with the intrauterine development of a nearly totally occlusive thrombus in the umbilical vein is presented. Etiologic considerations are discussed.