Pregnancy & Placental Pathology

Question 1

Answer 1

Fetal side of the placenta

Question 2

Answer 2

Maternal side of the placenta

Question 3

Umbilical vein brings blood (in/out) the placenta.

Umbilical arteries bring blood (in/out) the placenta.

Answer 3

Umbilical vein brings blood OUT of the placenta.

Umbilical arteries bring blood IN the placenta.

Question 4

What is the histological composition of the Umbilical Cord?

Answer 4

2 arteries, 1 vein

Wharton’s jelly (gelatinous polysaccharide)

Question 5

What are some examples of cord abnormalities? (4)

Answer 5

• Marginal insertion (edge of disk)
• Velamentous insertion (into membranes)
• Knots
• Pseudoknots

Question 6

Answer 6

Cord entanglement

Question 7

Answer 7

Funisitis (cord inflammation)

Blood & neutrophils

Ascending infections of amniotic fluid

Question 8

What are the different types of placental membranes? (3)

Answer 8

• Amnion
• Chorion laeve
• Decidua capsularis

Question 9

What type of staining is this?

Answer 9

Meconium staining

Yellow-brown pigment laden MΦ

Question 10

Answer 10

Chorioamnionitis

Maternal neutrophils

From decidua to surface

Question 11

What is the composition of the placental disk? (3)

Answer 11

• Amnion
• Chorionic plate & chorion frondosum
  
  • Chorion frondosum = chorionic villi
• Fetal vessels

Question 12

What is the composition of the trophoblast?

Answer 12

• Syncytiotrophoblast
• Cytotrophoblast
• Intermediate trophoblast

Question 13

Answer 13

Oligohydramnios

Question 14

What does fetal vasculopathy look like on histology?

Answer 14

Hypertrophic vessels

Thrombosed vessels

Not a lot of oxygen exchange

Question 15

What does the maternal decidua look like on histology?

Answer 15

Decidua basalis

Large decidual cells

Smattering of lymphocytes (triggers labor)

Not pathologic

Question 16

Answer 16

Placental Abruption

Maternal surface

Arteries of mother’s uterine wall

Impeded blood flow –> clot

Question 17

What are the 4 types of implantation abnormalities?

Answer 17

• Previa - over cervix
• Accreta - into the myometrium
• Increta - deeper into the myometrium
• Percreta - through the uterine wall

Question 18

What does the villous parenchyma look like on histology?

Answer 18

• Chorionic villi
• Fetal stem vessels & villous capillaries
  
  • Fetal blood
• Intervillous space (maternal blood)

Question 19

What does distal villous hypoplasia look like on histology?

Answer 19

• Terminal villi don’t have capillaires (avascular)
• Leads to intrauterine growth restriction, placental insufficiency

Question 20

Answer 20

• Parenchymal Infarctions
• Death of villi due to lack of oxygen
• Ischemic necrosis
• No remodeling (just death)
• Small & peripheral infarction less clinically significant than one that is large & central

Question 21

Answer 21

Infarction

Question 22

What are the two types of placental infection?

Answer 22

• Ascending
  
  • From GI/GU tract
  • Bacterial
• Hematogenous
  
  • Via maternal blood, into placenta
  • Viral (infection visible in villi)

Question 23

Placental Infection

Fetal response

Maternal response

Answer 23

• Fetal response
  
  • Leukocytes from fetal blood vessels into cord & chorionic plate
• **Maternal response **
  
  • Leukocytes from decidual vessels into membranes & from intervillous space into villi

Question 24

**Ectopic Pregnancy **

Definition

Answer 24

• Implantation of fertilized ovum anywhere other than the uterine cavity (1% of all pregnancies)
  
  • 90% tubal
  • Ovaries
  • Peritoneal surfaces of the abdomen

Question 25

**Ectopic Pregnancy** Risk Factors

Answer 25

* Anything that obstructs the tubes * Chronic inflammation (salpingitis, PID) * Tubal ligation

Question 26

**Ectopic Pregnancy** Early stages Eventually

Answer 26

* Early stages of pregnancy _unremarkable_ * ß-hCG increases normally * Menstruation stops * Eventually * Embryo may die due to inadequate attachment * Placental invasion causes rupture w/ massive _hemorrhage_ & _shock_

Question 27

What are the 3 types of **Gestational Trophoblastic Disease**?

Answer 27

* Hydatiform mole (complete & partial) * Invasive mole * Choriocarcinoma

Question 28

**Molar Pregnancy** Definition

Answer 28

* Arises from **2 sperm** fertilizing an *empty* (complete mole) or *normal* (partial mole) egg * Chorionic villi **swollen, edematous, grape-like** * Produces ß-hCG

Question 29

**Complete Mole vs. Partial Mole** * Karyotype * Villous edema * Trophoblast proliferation * Atypia * Serum hCG * Behavior * p57 staining * Fetus

Answer 29

Question 30

**Invasive Moles** Definition

Answer 30

* 10% of gestational trophoblastic disease * **Complete mole w/ invasive behavior** * No metastatic potential

Question 31

**Choriocarcinoma** Definition

Answer 31

* 2-3% of gestational trophoblastic diseae * **Very aggressive, malignant neoplasm** * 50% occur in the setting of complete mole, others after SAB or normal pregnancy * Highly chemosensitive

Question 32

**Pre-eclampsia/eclampsia** Definition

Answer 32

* **HTN + edema + proteinuria in 3rd trimester** * 5-10% of all pregnancies * More common in older women * **w/ seizures = eclampsia** * Can be accompanied by DIC & multisystem organ failure * Treated symptomatically, but need to deliver baby

Question 33

**Pre-eclampsia/eclampsia** Histology

Answer 33

* Inadequate maternal blood flow to the placenta due to **incomplete remodeling of the spiral arteries ** * Instead of muscular layer, trophoblast lining * _Trophoblasts don't contract _ * Wide open blood flow

Question 34

What are 3 types of **placental malignancy**?

Answer 34

* **Primary placental tumors** * Hydatidiform moles * Choriocarcinoma * **Metastatic disease from mother** * Melanoma * Breast * Others (rarely) * \*intervilli space\* * **Fetal tumors** * Neuroblastoma * \*villus capillaries\*