PATH: Placenta

Question 1

What is the temporary organ connecting fetus and mother providing the equivalent of respiratory (and renal) services?

Answer 1

placenta

Question 2

What is the membranous sac surrounding fetus containing serous fluid essential for fetal development?

Answer 2

amnion

Question 3

What is the plate-shaped tissue under part of amniotic sac containing fetal blood vessels that branch into villi projecting into space filled with maternal blood?

Answer 3

chorion

Question 4

What is the outer layer of blastocyst (from fertilized ovum) that implants in uterus and forms placenta?

Answer 4

trophoblast

Question 5

What is the outer layer of placenta that normally peels off myometrium and sheds with placenta?

Answer 5

decidua

Question 6

What are the syncytium of cells forming outer covering of chorionic villi, which thin out their cytoplasm and let their clumped nuclei hang off villi in “syncytial knots” to minimize diffusion barrier?

Answer 6

syncytiotrophoblast

Question 7

What is the inner layer of the 1st trimester chorionic villi called?

Answer 7

cytotrophoblast layer

Question 8

What is the outer layer of the 1st trimester chorionic villi called?

Answer 8

syncytiotrophoblast layer

Question 9

How do third trimester chorionic villi differ from first trimester?

Answer 9

more blood vessels, less interstitium, thinner trophoblast covering

Question 10

Where is a rupture of an ectopic pregnancy likely to occur?

Answer 10

lower abdominal cavity or pelvis (rather than into the uterus)

Question 11

When someone presents with long-term bleeding 1 month after their LNMP, what should you think of?

Answer 11

spontaneous abortion

Question 12

What test should you get in a person who has been bleeding for days?

Answer 12

hemoglobin

Question 13

Why might a person who has been bleeding for days have a normal blood pressure?

Answer 13

they are young! young people will compensate for a tremendously long time with deceptively normal vital signs until they reach the compensatory limits of their young hearts and die in a flash.

Question 14

If you expect your patient has a bleeding disorder like von Willebrand disease, what test can you use to screen?

Answer 14

partial thromboplastin time

Question 15

When you see very young/ very old southeast Asian (Indonesian) pregnant women, what should you think of?

Answer 15

hydatidiform mole

Question 16

What is a hydatidiform mole?

Answer 16

Abnormal gestations due to two sperm fertilizing one egg, or one or two sperm fertilizing an “empty egg” with absent or nonfunctional DNA

Question 17

What type of moles are triploid?

Answer 17

partial moles

Question 18

What type of moles are diploid?

Answer 18

complete moles

Question 19

What is the pathological appearance of chorionic villi in hydatidiform moles?

Answer 19

Cystic swelling of chorionic villi makes them resemble grapes

Question 20

Which type of mole will get trophoblastic hyperplasia (all the way around the villi)?

Answer 20

complete moles

Question 21

When are hydatidiform moles usually diagnosed?

Answer 21

Diagnosed at average of 8.5 weeks

Question 22

What findings are diagnostic of hydatidiform mole?

Answer 22

abnormal (snow storm) ultrasound showing diffuse villous enlargement and/or abnormally rapid and high elevation of beta human chorionic gonado-tropin (beta-HCG)

Question 23

How do you manage a hydatidiform mole?

Answer 23

curettage (scaping out the uterine contents) and monitoring beta-HCG to make sure it is all out

Question 24

In someone with extreme blood loss (who has retained tons of salt in water to compensate), immediate blood transfusion via large bore catheters in all 4 limbs can kill a patient by what cause?

Answer 24

flash pulmonary edema

Question 25

In what cases should a frozen section be performed?

Answer 25

only in cases that will change patient management

Question 26

Sudden onset of dyspnea during labor and delivery is a classic manifestation of what?

Answer 26

amniotic fluid embolism

Question 27

What can cause sudden death due to a cardiac arrhythmia and it causes pulmonary edema due to heart failure (that usually causes a gradual onset of dyspnea over minutes)?

Answer 27

peripartum cardiomyopathy

Question 28

The risk of a PE is increased by how much during pregnancy?

Answer 28

increased up to 50-fold

Question 29

How many pregnancies are complicated by pulmonary thromboembolism?

Answer 29

1 in 500

Question 30

When do pregnant women get PE and why?

Answer 30

more commonly during & after delivery than before because that releases compression of the IVC

Question 31

Where do the majority of PEs come from?

Answer 31

deep vein thrombosis in left leg

Question 32

What is a life-threatening obstetric emergency due to acute cardio-pulmonary failure from pulmonary vasospasm, hypertension and right heart failure triggering pulmonary diffuse alveolar damage, sometimes with a second phase of DIC and hemorrhage?

Answer 32

amniotic fluid embolism

Question 33

Why do amniotic fluid emboli occur?

Answer 33

fetal and amniotic elements entering maternal veins as decidua detaches and embolizing to lungs, which react with vasospasm, etc.

Question 34

Is amniotic fluid embolism fatal for babies?

Answer 34

not usually but around 20% die if their mothers die

Question 35

List the differential diagnosis for acute onset dyspnea during labor and deilvery.

Answer 35

``` Pulmonary thromboembolism Pulmonary edema (if pre-eclamptic) Peripartum cardiomyopathy Amniotic fluid embolism Anxiety Magnesium sulfate toxicity (if on magnesium sulfate for eclampsia) ```

Question 36

What race has the highest incidence of maternal death?

Answer 36

black women

Question 37

What are the 5 leading causes of maternal death?

Answer 37

``` thromboembolism (20%) hemorrhage (17%) pre-eclampsia (16%) infection (13%) cardiomyopathy (8%) ```

Question 38

Where is the most common site of ectopic pregnancies?

Answer 38

fallopian tube (90%)

Question 39

What is the most common cause of ectopic pregnancy?

Answer 39

scarring from previous infection of tube

Question 40

When and how does ectopic pregnancy usually present?

Answer 40

acute severe abdominal pain due to fallopian tube rupture and pelvic hemorrhage, about 6 weeks after last menses

Question 41

What are the most severe consequences of an ectopic pregnancy?

Answer 41

hemorrhagic shock, death

Question 42

What is a Spontaneous Abortion (Miscarriage)?

Answer 42

Pregnancy loss before 20 weeks

Question 43

True or False: spontaneous abortions are most common in older women.

Answer 43

TRUE: 11% in pregnancies of 20-24 year-olds to 51% in 40-44 year-olds

Question 44

What is the most common cause of spontaneous abortion in the first trimester?

Answer 44

GENETIC: half with chromosomal abnormalities

Question 45

What is the most common cause of spontaneous abortion in the second trimester?

Answer 45

INFECTIOUS (acute chorioamnionitis)

Question 46

What is the most common cause of spontaneous abortion in the third trimester?

Answer 46

VASCULAR (uteroplacental insufficiency, commonly associated with pre-eclampsia)

Question 47

What autoimmune disease is commonly associated with spontaneous abortion?

Answer 47

antiphospholipid syndrome

Question 48

What is : implantation in lower uterus or cervix, sometimes covering internal cervical os?

Answer 48

placenta previa

Question 49

What is: defective decidua, with adherence of villous tissue to myometrium?

Answer 49

placenta accreta (most common)

Question 50

What is: defective decidua, with penetration of villous tissue into myometrium?

Answer 50

placenta increta

Question 51

What is: defective decidua, with penetration of villous tissue through entire uterine wall?

Answer 51

placenta percreta (least common)

Question 52

True or false: all twins with Dichorionic diamniotic placentas are dizygotic?

Answer 52

false! 80% are dizygotic

Question 53

True or false: all twins with monochorionic | placentas are monozygotic?

Answer 53

true! if you share a placenta, you are identical

Question 54

In what type of placenta do you see twin-twin transfusion syndrome?

Answer 54

Monochorionic monoamniotic

Question 55

What is twin-twin transfusion syndrome?

Answer 55

unbalanced vascular anastomoses in monochorionic placentas can cause one twin to get too much blood and the other too little

Question 56

How might the "donor" twin in twin-twin transfusion syndrome affect its surroundings?

Answer 56

can send necrotic procoagulant material into the anastomoses threatening the life of the other twin and the mother

Question 57

List the common causes of placental infections.

Answer 57

``` TORCH T for Toxoplasma gondii O for Other (syphilis, HIV, etc.) R for Rubella (German measles) C for Cytomegalovirus H for Herpes simplex virus ```

Question 58

How does acute chorioamnionitis (also called intra-amniotic infection) occur?

Answer 58

ascends from vagina

Question 59

What is the protozoan from cat feces that causes microcephaly, fever, rash, and seizures in neonates?

Answer 59

Toxoplasma gondii

Question 60

What infection is actually protracted intrapartum from maternal genital lesions, causes skin infection & worse in neonates, and is preventable with C section?

Answer 60

HSV

Question 61

What placental infection causes deafness, neurologic defects, and cardiac malformations in neonates?

Answer 61

rubella

Question 62

What is the most common transplacental infection | in US? What are the symptoms?

Answer 62

Cytomegalovirus (causes deafness, neurologic | defects in neonates)

Question 63

When do women with Acute Chorioamnionitis typically have rupture of membranes?

Answer 63

41% of women with premature rupture of membranes at <27 weeks

Question 64

Describe the stages of neutrophil movement in acute chorioamnionitis?

Answer 64

intervillous space--> chorion --> amnion --> fetal polys in chorionic blood vessels (fetal vasculitis where inflammation may lead to thrombosis)

Question 65

What is funisitis?

Answer 65

Exudate and congestion of cord (seen in placental infections)

Question 66

What is the characteristic pathology of placental infections?

Answer 66

Extensive tan (or green) exudate (and areas of congestion) on the amniotic surface with funisitis

Question 67

When you see the word INFLAMMATION, what should you automatically think?

Answer 67

pro-coagulant

Question 68

What is the major immune response to Acute Chorioamnionitis?

Answer 68

maternal neutrophiis

Question 69

What are the two major side effects of placental infeciton?

Answer 69

premature rupture of membranes and premature labor and delivery

Question 70

What is the causative agent of acute chorioamnionitis?

Answer 70

polymicrobial, with multiple vaginal flora bacteria

Question 71

What are the possible fetal implications of chorioamnionitis?

Answer 71

fetal sepsis, cerebral palsy, endometritis

Question 72

What normally occurs when trophoblast cells invade | myometrial spiral arteries?

Answer 72

destroy the smooth muscle cells in their walls and convert them from small caliber resistance vessels to large caliber capacitance vessels that accommodate vastly increased blood flow later in gestation

Question 73

What is the name of the truncated form of VEGF receptor that acts as a decoy that is secreted by ischemic placenta in pre-eclampsia?

Answer 73

soluble fms-like tyrosine kinase 1 (sFlt-1)

Question 74

What is the name of the form of TGF-beta receptor that acts as a decoy that is secreted by ischemic placenta in pre-eclampsia?

Answer 74

soluble endoglin

Question 75

What are the roles of sFIt-1 and endoglin?

Answer 75

block VEGF and TGF mediated production of nitric oxide and prostacyclin, causing maternal hypertension, proteinuria and edema

Question 76

Why is preeclampsia a procoagulant state?

Answer 76

partly due to blockage of prostacyclin production and the production of proinflammatory cytokines like tumor necrosis factor alpha (TNF-alpha)

Question 77

What is HELLP syndrome?

Answer 77

Hemolysis, Elevated Liver enzymes and Low Platelets

Question 78

What is eclampsia?

Answer 78

cerebral edema and seizures

Question 79

The changes that occur to the placental arteries by pre-eclampsia mirror what disease?

Answer 79

atherosclerosis

Question 80

What is the initial effect of ischemia on the development of chorionic villi (via preeclampsia)?

Answer 80

accelerated maturation that makes them more efficient at gas exchange, nutrient import and waste export, but when ischemia becomes more severe, it results in villous hypoplasia.

Question 81

What disease is characterized by: activation of platelets and clotting factors, creating fibrin red cell shredders in capillaries that causes hemolysis, platelet aggregation lowering the count, and thrombi in liver sinusoids that injure hepatocytes, who release their enzymes.

Answer 81

HELLP syndrome

Question 82

The liver injury of HELLP syndrome can progress to what problems?

Answer 82

necrosis, hemorrhage, even liver rupture

Question 83

What is the most common cause of Placental Ischemia and Infarction?

Answer 83

Pre-eclampsia

Question 84

How much ischemia of the placenta can the fetus tolerate?

Answer 84

the fetus can tolerate infarction of more than 50% of the placenta

Question 85

What are the repercussions of extensive ischemia of the placenta?

Answer 85

intrauterine growth restriction, neurologic injury and fetal demise

Question 86

What is an "invasive mole"?

Answer 86

a mole that persists after therapy and looks like a choriocarcinoma but has not metastasized

Question 87

What are the common sites of metastatic | choriocarcinoma?

Answer 87

brain, lung, liver, spleen and kidney

Question 88

How does a choriocarcinoma spread?

Answer 88

hematogenously (like a sarcoma)

Question 89

What is the most common first symptom of a choriocarcinoma?

Answer 89

uterine bleeding

Question 90

What is a word for a deficiency of amniotic fluid?

Answer 90

oligohydramnios

Question 91

What does oligohydramnios due to the infant?

Answer 91

sequence of compressive injuries to the fetus, but also pulmonary hypoplasia because the fetus needs to “breathe” for normal lung development, and absence of fetal “urine” in amniotic fluid due to fetal renal disease causes pulmonary hypoplasia incompatible with life after birth

Question 92

Describe some features of the oligohydramnios sequence.

Answer 92

Contractures of hands and feet (more severe deformation = clubfeet); Potter facies (flattened face, especially nose and ears)

Question 93

What is the name for a mechanical fibrotic lesion causing limb strictures or amputations?

Answer 93

Amniotic band

Question 94

What disease has: bleeding at the decidual-placental interface causing placental detachment before delivery of the fetus?

Answer 94

placenta abruption

Question 95

What is the immediate cause of placental abruption?

Answer 95

rupture of decidual blood vessels

Question 96

2/3 of placental abruptions lead to what?

Answer 96

retroplacental hematoma

Question 97

What percentage of retroplacental hematomas are due to placental abruptions?

Answer 97

2/3

Question 98

What are the 2 consequences of peripartum cardiomyopathy?

Answer 98

resolves spontaneously (in 1/3) or leads to dilated cardiomyopathy (in 2/3)

Question 99

Peripartum cardiomyopathy is most popular in what populations?

Answer 99

multiparous African-Americans

Question 100

How do you diagnose peripartum cardiomyopathy?

Answer 100

dilated cardiomyopathy without another cause 3 months before or after delivery