Flashcards in Placental Pathology Deck (24)
Review: What are the the two layers / cells types of trophoblasts?
Inner, mononuclear cytotrophoblasts.
What happens to uterine vascular during secondary / late placentation?
Spiral arteries get remodeled to form low-pressure arterial blood flow, notably there is a loss of smooth muscle.
(at points, the arteries are plugged with invading trophoblasts)
When do most spontaneous abortions occur?
Before 20 weeks.
Where is Wharton's Jelly? What is its role?
In the umbilical cord. It's thought to be a shock-absorber for the vessels.
3 layers of the placenta?
Amnion, chorion, decidua.
Big picture of indications for placental examination? (Why not examine all placentas?)
History of reproductive failure, maternal conditions that could cause problems, observed irregularities in the fetus/placenta.
(Examining all placentas isn't a good use of resources.)
3 mechanisms of disease in the placenta?
Inflammation (due to infection).
Two pathways for placental infection? Which are more likely to cause symptoms in mom?
Ascending from lower reproductive tract.
Ascending infectious are more likely to produce symptoms.
Difference in common sites of inflammation between ascending and hematogenous infection?
Ascending: more membranes (chorioamnitis) and cord (fusitis.
Hematogenous: more chorionic villi (villitis)
Organisms commonly causing ascending placental infection? (name 4)
E. coli, Group B Strep, fusobacterium, mycoplasma
Organisms commonly causing hematogenous placental infection? (name 4)
Viruses, toxoplasma, syphilis, other bacteria during maternal sepsis.
Which is more likely to cause pre-term delivery: Ascending or hematogenous infection?
Why is villitis so bad?
The fetus can't get as much oxygen/nutrition.
Can the umbilical cord become knotted?
Yep. Sometimes this is really bad, sometimes it doesn't impede blood flow.
What is placental abruption actually? What's a common cause of it?
Retroplacental hemorrhage because placenta has separated from the uterus.
Often caused by hypertension. (can be secondary to cocaine use)
What happens to the villi when abruption happens?
3 signs of pre-eclampsia?
Hypertension, proteinuria, and edema.
Anatomic cause of pre-eclampsia / eclampsia?
Superficial placental implantation.
Spiral arteries don't appropriately remodel - they're too thick and muscular.
What can happen to the spiral arteries in pre-eclampsia? What does this look like on histology?
On histology, there is fibrinoid necrosis and lumens filled with foamy macrophages.
What's a chorioangioma?
Benign local proliferation of blood vessels and stroma.
What happens in complete molar pregnancy?
1 sperm fertilizes an empty ovum and duplicates OR
2 sperm fertilize an empty ovum.
What happens in a partial molar pregnancy?
2 sperm fertilize a normal ovum.
Which type of molar pregnancy has more embryonic development? Which is associated with higher trophoblastic tumor risk?
Partial molar has more differentiated tissues etc.
Complete molar has higher risk for trophoblast tumor.