umbilical vein injury, follow-up acute atherosis

The photomicrograph is from one of the cases for the perinatal care committee meeting at one of the hospitals that sends us placentas. This previously uncomplicated term pregnancy required an emergency Cesarean section for non-reassuring fetal heart rate tracing. The infant Apgars were 1 at 1 minute and 5 at minutes. The loss of muscle in the section of umbilical vein can be found on random sections of umbilical vein in uncomplicated pregnancies. I have more examples and a discussion on the web site (pediatricperinatalpathology.com) under umbilical cord hemorrhage. The unusual feature in this case is the subendothelial pink material. This could be the lesion that caused underlying ischemic atrophy of the media, or it could be evidence of an active injury of endothelium with fibrin and serum protein. I can not directly relate the lesion to the history of fetal distress, but is tempting to think that weakness in the media could lead to kinking and collapse of the lumen with fetal distress.

More on acute atherosis without preeclampsia: Yesterday, I signed out a placenta with an old retroplacental hemorrhage with overlying infarction of 40% of the surface (essentially an old abruption or premature placental separation). This mother had acute atherosis in a previous pregnancy with multiple infarctions, a second pregnancy with multiple placental infarctions, and the current case which did not have infarctions, but had this separation at 31 weeks. I will post a discussion of retroplacental hemorrhage on the web site soon.