Pathology of Placenta

Question 1

What is a spontaneous abortion?

Answer 1

• miscarriage of fetus before 20 weeks gestation (usually 1st trimester).
• presents with vaginal bleedings, cramp-like pain, and passage of fetal tissues.
• occurs in up to 1/4 of pregnancies.

Question 2

What causes most spontaneous abortions?

Answer 2

• CHROMOSOMAL ANOMALIES (trisomy 16)
• others include hypercoagulable stages (antiphospholipid syndrome, lupus), congenital infection, and exposure to teratogens (especially during first 2 weeks).

Question 3

What weeks of gestational development tend to cause organ malformation?

Answer 3

• weeks 3-8

Question 4

** What is PLACENTA PREVIA?

Answer 4

• implantation of the placenta in the lower uterine segment; placenta overlies cervical os (opening).
• think you are getting a “PREVIEW” of the placenta because you can see it.

Question 5

How does PLACENTA PREVIA present?

Answer 5

• 3rd trimester bleeding and often requires C-section delivery.

Question 6

** What is PLACENTAL ABRUPTION?

Answer 6

• separation of placenta from the decidua prior to delivery of the fetus.
• presents with 3rd trimester bleeding and fetal insufficiency.

Question 7

Is Placental Abruption a common cause of still birth?

Answer 7

YES

Question 8

** What is PLACENTA ACCRETA?

Answer 8

• improper implantation of placenta into the myometrium with little or no intervening decidua.
• presents with difficult delivery of the placenta and postpartum bleeding.

Question 9

What does Placenta ACCRETA often require?

Answer 9

• hysterectomy.

Question 10

*** What may be seen in the vessels of the placenta in a mother with preeclampsia?

Answer 10

• Fibrinoid necrosis

Question 11

What is Sudden Infant Death Syndrome?

Answer 11

• death of healthy infant (1 month to 1 year old) without obvious cause.
• usually expire during sleep

Question 12

What are the risk factors for sudden infant death syndrome?

Answer 12

• sleeping on stomach
• cigarette smoke
• prematurity

Question 13

** What is HYDATIDIFORM MOLE?

Answer 13

• abnormal conception characterized by swollen and edematous villi with proliferation of trophoblasts. (cells that surround the villi).
• uterus expands as if normal pregnancy, but BIGGER than normal.

Question 14

Will b-hCG be higher or lower in HYDATIDIFORM MOLE?

Answer 14

• HIGHER

Question 15

How does HYDATIDIFORM MOLE present without prenatal care?

Answer 15

• passage of GRAPE-LIKE masses in early 2nd trimester through the vaginal canal.

Question 16

How is HYDATIDIFORM MOLE diagnosed WITH prenatal care?

Answer 16

• “SNOW-STORM” appearance on US in early 1st trimester.

- fetal heart sounds absent.

Question 17

How are molar pregnancies classified?

Answer 17

• as COMPLETE or PARTIAL.

* based on genetics, fetal tissue, villous edema, trophoblastic proliferation, and risk for choriocarcinoma.

Question 18

** How should we think about a COMPLETE molar pregnancy?

Answer 18

• as most things in life, this is COMPLETELY DAD’S fault: 2 sperm fertilizing an empty egg cause COMPLETE mole bc this is COMPLETELY dad’s (PATERNAL) fault and thus 46 chromosomes bc 2 sperm.
• Bc this is COMPLETELY a mole, there is no other fetal tissue (aka fetal tissue absent).
• all villi are edematous/hydropic (i.e. they are COMPLETELY edematous).
• COMPLETE proliferation of trophoblsts all around the hydropic villi.
• B-hCG is higher here bc you have more trophoblastic proliferation.
• complete mole has a greater risk; 2-3% (i.e. COMPLETE risk) for choriocarcinoma.
• may see HYPERthyroidism.
• will not see embryological parts.

Question 19

** How should we think about a PARTIAL molar pregnancy?

Answer 19

• a normal egg is fertilized by 2 sperm= 69 chromosomes.
• this is PART fetal tissue and PART mole so fetal tissue will be present.
• villi will be PARTIALLY edematous.
• PARTIAL trophoblastic proliferation around hydropic villi.
• PARTIAL risk for choriocarcinoma (i.e. lower risk).
• will often see embryo parts.

Question 20

How do you treat a molar pregnancy?

Answer 20

• dilation and curettage (D&C)

- subsequent B-hCG monitoring to ensure adequate mole removal and to screen for choriocarcinoma.

Question 21

** What is CHORIOCARCINOMA?

Answer 21

• tumor of TROPHOBLASTS that arises as a complication of GESTATION (spontaneous abortion, normal pregnancy, or hydatidiform mole) or as a spontaneous GERM cell tumor.
• NO VILLI.
• hCG and KERATIN +

Question 22

What cells secrete B-hCG?

Answer 22

• syncytiotrophoblasts

Question 23

** Does the GESTATIONAL pathway or GERM CELL pathway leading to choriocarcinoma respond best to chemotherapy?

Answer 23

• GESTATIONAL pathway (usually after a MOLE)

* germ cell pathway does NOT respond well to chemo.

Question 24

What are the 2 ways placental infections can occur?

Answer 24

1. ASCENDING through birth canal (more common).

2. HEMATOGENOUS route (ransplacental).

Question 25

What may indicate placental infection?

Answer 25

• cloudy amniotic fluid with purulent exudate.

- may have inflammation of the umbilical vessels.

Question 26

*** What are the TORCH infections?

Answer 26

• Toxoplasmosis, Trepanema (syphilis), TB
• Rubella
• CMV
• HSV
• Listeria

Question 27

With what is chronic vilitis associated?

Answer 27

• intrauterine growth retardation.
• stillbirths
• look for inflammation of the placental maternal side.

Question 28

** What is acute FUNISITIS?

Answer 28

• inflammation of the UMBILICAL CORD.

Question 29

** What is placental infarct?

Answer 29

• area of VILLOUS NECROSIS due to local obstruction of the maternal uteroplacental circulation.
• Fresh infarct is DARK RED and FIRMER than surrounding tissue.
• high incidence of NEONATAL ASPHYXIA, LOW BIRTH WEIGHT, and INTRAUTERINE DEMISE.

Question 30

What can cause placental infarct?

Answer 30

• placental abruption (abruptio placentae).

Question 31

*** What marker will you see in PARTIAL moles that is absent in complete moles?

Answer 31

• p57 (cell cycle inhibitor)

Question 32

** What is an INVASIVE mole?

Answer 32

• usually a complete mole, that PENETRATES deeply into the MYOMETRIUM, leading to significant hemorrhage.
• contains villi.