Placental Pathology

Question 1

Review: What are the the two layers / cells types of trophoblasts?

Answer 1

Inner, mononuclear cytotrophoblasts.

Outer, syncytiotrophoblasts.

Question 2

What happens to uterine vascular during secondary / late placentation?

Answer 2

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)

Question 3

When do most spontaneous abortions occur?

Answer 3

Before 20 weeks.

Question 4

Where is Wharton’s Jelly? What is its role?

Answer 4

In the umbilical cord. It’s thought to be a shock-absorber for the vessels.

Question 5

3 layers of the placenta?

Answer 5

Amnion, chorion, decidua.

Question 6

Big picture of indications for placental examination? (Why not examine all placentas?)

Answer 6

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.)

Question 7

3 mechanisms of disease in the placenta?

Answer 7

Inflammation (due to infection).
Vascular lesions.
Neoplasms.

Question 8

Two pathways for placental infection? Which are more likely to cause symptoms in mom?

Answer 8

Ascending from lower reproductive tract.
Hematogenous.
Ascending infectious are more likely to produce symptoms.

Question 9

Difference in common sites of inflammation between ascending and hematogenous infection?

Answer 9

Ascending: more membranes (chorioamnitis) and cord (fusitis.
Hematogenous: more chorionic villi (villitis)

Question 10

Organisms commonly causing ascending placental infection? (name 4)

Answer 10

E. coli, Group B Strep, fusobacterium, mycoplasma

Question 11

Organisms commonly causing hematogenous placental infection? (name 4)

Answer 11

Viruses, toxoplasma, syphilis, other bacteria during maternal sepsis.

Question 12

Which is more likely to cause pre-term delivery: Ascending or hematogenous infection?

Answer 12

Ascending.

Question 13

Why is villitis so bad?

Answer 13

The fetus can’t get as much oxygen/nutrition.

Question 14

Can the umbilical cord become knotted?

Answer 14

Yep. Sometimes this is really bad, sometimes it doesn’t impede blood flow.

Question 15

What is placental abruption actually? What’s a common cause of it?

Answer 15

Retroplacental hemorrhage because placenta has separated from the uterus.
Often caused by hypertension. (can be secondary to cocaine use)

Question 16

What happens to the villi when abruption happens?

Answer 16

Ischemic infarct.

Question 17

3 signs of pre-eclampsia?

Answer 17

Hypertension, proteinuria, and edema.

Question 18

Anatomic cause of pre-eclampsia / eclampsia?

Answer 18

Superficial placental implantation.

Spiral arteries don’t appropriately remodel - they’re too thick and muscular.

Question 19

What can happen to the spiral arteries in pre-eclampsia? What does this look like on histology?

Answer 19

Acute atherosis.

On histology, there is fibrinoid necrosis and lumens filled with foamy macrophages.

Question 20

What’s a chorioangioma?

Answer 20

Benign local proliferation of blood vessels and stroma.

Question 21

What happens in complete molar pregnancy?

Answer 21

1 sperm fertilizes an empty ovum and duplicates OR

2 sperm fertilize an empty ovum.

Question 22

What happens in a partial molar pregnancy?

Answer 22

2 sperm fertilize a normal ovum.

Question 23

Which type of molar pregnancy has more embryonic development? Which is associated with higher trophoblastic tumor risk?

Answer 23

Partial molar has more differentiated tissues etc.

Complete molar has higher risk for trophoblast tumor.

Question 24

4 trophoblast-derived tumors?

Answer 24

Invasive mole.
Choriocarcinoma.
Placental site trophoblastic tumor.
Epithelial trophoblastic tumor.