Placenta

Question 1

The placenta is composed of two layers the amnion (inner layer) and the chorion the outer layer, what does the chorion attach to?

Answer 1

decidua=endometrium of pregnancy

Question 2

What is the chorionic villi?

Answer 2

placenta composed of chorionic villi that sprout from the chorion to provide large contact area between fetal and maternal circulation
_BLOOD DOES NOT MIX

1. central stroma
2. epithelium
   - syncytiotrophoblast
   - cytotrophoblast

-3rd trimester villi are smaller and vasculature more pronounced and see fibrosis

Question 3

Spontaneous abortion

Answer 3

lost before 20 weeks
1/3 of all pregnancies lost
-more than half due to chromosomal abnormalities
-defective implantation
-fetal abnormalities
-maternal causes (inflammation, uterine deformity, DM, luteal-phase defects)
-unkown

Question 4

Ectopic Pregnancy

Answer 4

Implantation occurs outside uterus
1:150 pregnancies
90% fallopian tubes
10% ovary and abdominal cavity

Predisposing factors

• inflammation and scarring
• intrauterine device

Presentation-abdominal pain, acute abdomen

Clinical complications: rupture and hemorrhage; high mortality unless removed surgically

Question 5

Dizygotic

Answer 5

fertilization of 2 ova

Question 6

Monozygotic

Answer 6

division of one fertilized ovum

Question 7

Monochorionic placenta implies what? What is the number of amnions determined by?

Answer 7

monozygotic (identical twins)
-time of the splitting of the ovum
monochorionic diamniotic vs monochorionic mononamnionic

Question 8

Placenta previa

Answer 8

attachment of placenta to lower uterine segment of cervix

-serious 3rd trimester bleeding-dilation of cervix disrupts placenta

Question 9

Placenta accreta

Answer 9

• partial or complete absence of decidua with adherence of decidua with adherence of placental villous tissue directly to myometrium -failure of placental separation
• cause of postpartum bleeding

Predisposing factors:

• placenta previa (60%)
• previous cesarean section

Question 10

abruptio placentae

Answer 10

premature separation of placenta prior to delivery

formation of retroplacental blood clot

• blood supply of oxygen and nutrients to fetus compromised to greater degree with increasing size of abruption
• painful maternal bleeding
• potential fetal death

Question 11

What happens if the placent tissue is retained postpartum?

Answer 11

postpartum hemorrhage

-potential infection

Question 12

preeclampsia-eclampsia

Answer 12

systemic syndrome characterized by widespread maternal endothelial dysfunction presenting clinically during pregnancy with:
hypertension
edema
proteinuria

• most common with 1st pregnancies
• usually last trimester

Question 13

What is the pathogenesis of preeclampsia-eclampsia?

Answer 13

placenta plays a key role
-symptoms rapidly disappear after delivery of placent

Principle theories

1. abnormal placenta vasculature
   - failure of uterine spinal artery to remodel-maternal vascular hypoperfusion-placental ischemia-generalized endothelial cell injury (cytotrophoblasts allow for arteries to remodel)
2. endothelial dysfunction and imbalance of angiogenic and anti-angiogenic factors
3. coagulation abnormalities

Question 14

What generalized processes also happen in preeclampsia-eclampsia? what happens to the placenta?

Answer 14

Generalized
liver: fibrin thrombi, hemorrhage, necrosis
kidney: fibrin in glomeruli and capillaries, renal cortical necrosis
brain: hemorrhage and thrombosis
heart and anterior pituitary

Placenta 
Malperfusion, ischemia, vascular injury
-infarcts
-retroplacental hematoma
-villous ischemia
-acute atherosis of uterine vessels ***-fibrinoid necrosis, macrophages, inflammation

Question 15

Preeclampsia

Answer 15

HTN, edema, proteinuria

Question 16

severe preeclampsia

Answer 16

preeclampsia + headaches and vision changes

Question 17

eclampsia

Answer 17

preeclampsia + convulsions

Question 18

HEELP syndrome

Answer 18

severe preeclampsia + hemolysis, elevated liver enzymes, low platelets

Question 19

WHat is the managment? Are there maternal sequelae after the birth?

Answer 19

Term=delivery
Preterm
-Mild-expectant management
-Severe-deliver regardless of fetal age

20% develop HTN and microalbuminuria within 7 years
-2X increased heart and brain vascular disease

Question 20

Placental infections

2 pathways

Answer 20

1. ascending
   - through birth canal
   - usually bacterial
   - result=premature rupture of membranes, pre-term delivery
2. Hematogenous
   - transplacental
   - TORCH

Question 21

What do you see in acute chorioamnionitis?

Answer 21

green purulent membranes

PMNS

Question 22

TORCH infections

Answer 22

T-toxoplasma gondii
O-others: parvovirus B 19, Syphilis, TB, listeria 
R-rubella
C-CMV
H-Herpes simplex virus, HIV

• all may evoke:
  1. fever
  2. encephalitis
  3. chorioretinitis
  4. hepatosplenomegaly
  5. pneumonitis
  6. myocarditis
  7. hemolytic anemia
  8. vesicular or hemorrhagic skin lesions

Question 23

Hydatidiform Moles

Answer 23

cystic swelling of chorionic villi with trophoblastic proliferation

• infrequent
• women present with miscarriage and undergo D&C based on US/HCG findings
• BENIGN-we want to know and distinguish them with regard to invasive mole or choriocarcinoma

Question 24

What chromosomes make up complete and partial moles?

Answer 24

Complete Mole 90%

• both chromosomes are of male origin
• homozygous complete mole
• 46XX

Complete Mole 10%

• both chromosomes are of male origin
• heterozygous complete mole
• 46XX and 46XY

Partial Mole MOST COMMON
Sperm and ovum
-69XXX, 69XXY, 69XYY

Question 25

``` Complete Mole General Gross Microscopic Clinical course ```

Answer 25

``` Most villi enlarged, edematous Diffuse trophoblast hyperplasia Androgenic (empty ovum) Embryo dies very early (fetal parts rarely seen) 2.5% risk of choriocarcinoma ``` Gross: Delicate friable mass of thin walled, translucent, cystic friable, grape like structures Microscopic - swollen villi with almost no fetal blood vessels - diffuse cytotrophoblast and syncytial trophoblast proliferation - marked atypia at implantation site ``` Clinical course Abnormal uterine bleeding passage of fluid and tissue ultrasound diagnostic (snow storm) -serum HCG increase -roved via curettage; serum HCG levels monitored -10% develop into invasive moles -2.5 risk choriocarcinoma ```

Question 26

Partial Mole | General

Answer 26

``` Some villi are edematous Minimal Trophoblastic proliferation One egg, two/three sperm Fetus, although abnormal, mostly present Not increased risk for choriocarcinoma ```

Question 27

``` Complete mole vs Partial mole Karyotype Villous edema Trophoblast proliferation Atypia Serum HCG Fetal TIssue Behavior ```

Answer 27

``` Complete Karyotype: 46 XX or 46XY Villous edema: all villi Trophoblast proliferation: diffuse, circumfrential Atypia: often present Serum HCG: elevated Fetal TIssue: absent Behavior: 2.5% choriocarcinoma ``` ``` Partial Karyotype: triploid Villous edema: some villi Trophoblast proliferation: focal; slight Atypia: absent Serum HCG: less elevated Fetal TIssue: present Behavior: rare ```

Question 28

Invasive Mole

Answer 28

Mole that penetrates uterine wall Hydropic chorionic villi invade myometrium -may embolize to distant sites Clinical vaginal bleeding persistently elevated HCG risk of uterine rupture Treatment chemotherapy

Question 29

Gestational Choriocarcinoma

Answer 29

Malignant - rapidly invasive, widely metastatic - rapidly growing - necrotic - hemorrhagic Neoplasm of trophoblast derived cells - proliferation neoplastic cytotrophoblasts and syncytiotrophoblast - NO CHORIONIC VILLI Uncommon 1:20,000-30,000 Us preg 50% from complete moles 25% from previous abortions 22% normal pregnancy (intraplacental choriocarcinoma) Ectopic pregnancy

Question 30

How does Gestational Choriocarcinoma present? What is the treatment?

Answer 30

Presents as vaginal blood, brown fluid spotting - during pregnancy, after miscarriage, after curettage - can be months delay Metastases usually at time of any signs HCG elevations -unless very necrotic Chemo EXTREMELY effective -paternal antigens evoke immune response in mother