Thrombosis of the umbilical cord vein: An unresolved dilemma, cause or effect of fetal demise?

Thrombosis of fetal umbilical cord (UC) vessels is a rare event and presumably affects  1/1300 of all fetal necropsies, 1/1000perinatal postmortems, 1/250 fetal autopsies of high risk pregnancies, 1/25 of fetal autopsies with cord abnormalities.. Even though, UC vessel trombosis is a major concern for late fetal distress and intrauterine demise, the casual mechanisms and related effects of thrombosis are not well understood. Umbilical cord thrombosis is not listed among factors associated with fetal death since its direct impact cannot be revealed. Despite a common pathologist-obstetrician intuition about a thrombus in the UC, concurrent maternal and/or fetal conditions prevent its acceptance as an independent factor. A patient with normal gestational follow-up findings presenting with fetal death in utero at 38 weeks’ gestation, whose post-mortem pathologic fetal investigation revealed thrombosis of the umbilical vein will be presented together with the review of literature.