Placental histologic criteria for umbilical blood flow restriction in unexplained stillbirth

Thrombosis of the umbilical vessels revisited. An observational study of 317 consecutive autopsies at a single institution

“…Our data are in agreement with what has been recently reported by Parast et al [14]. Their placenta histologic analysis in cases of stillbirth showed, especially in cases of unexplained fetal death, an elevated incidence of a histologic pattern suggestive of restricted umbilical blood flow (cord accident, 52% of the cases), although early thrombosis was not detectable through their study methodology.…”

“…In our series, early thrombosis of chorionic vessels was the most frequent lesion; and indeed, this finding is not surprising because subocclusive or occlusive clotting in tributaries of the umbilical vein or branches of umbilical arteries on the placental surface is often associated with the umbilical vessel thrombosis [22]. It is worth noting that, as pointed out by Parast et al [14], it is crucial to distinguish between thrombosis that happened in vivo and changes that developed postmortem. The chorionic vessel thrombosis may be associated with the presence of avascular villi in what is defined as fetal thrombotic vasculopathy (FTV) [13,23].…”

“…Recently, Parast et al [14] have pointed out that stillbirth due to a reduction of umbilical blood flow in the third trimester is greatly underestimated.…”

Hypoxic Patterns of Placental Injury: A Review

“…31 The clinical, umbilical cord compromise with focal placental lesions of decreased fetal blood flow, which is frequently a random pregnancy accident, did not correlate with diffuse PU, although they can produce the focal PU, so-called stasis-induced thrombotic vasculopathy, with clusters of avascular, fibrotic, and occasionally hemosiderotic chorionic villi. 64,65 Also, severe, mass-forming, congenital anomalies that interfere with blood return from the placenta to the fetus can produce the placental stasis-induced thrombotic vasculopathy, but not the diffuse PU.…”

A comparative study between the still births and full term normal deliveries based on the clinical history of mother

“…1,9 Many of the infants which are still born are normal phenotypically. 1 Placental lesions seen in cases of stillbirth are of interest from the clinical point of view and are frequently seen as having an important role in the cause. However, many of the placental changes seen in stillbirth are also witnessed in live births.…”