Pathology of the Placenta and Gestational Trophoblastic Disease Flashcards
How does ectopic pregnancy change hCG levels?
It delays/lowers the rise of hCG.
Trophoblastic disease presents with __________ hCG levels.
Initially delayed but then excessive hCG rise (that is, above 10,000 mIU/mL)
What is the discriminatory zone?
The DZ is the hCG range above which a uterine pregnancy should be visible on ultrasound.
What is gestational trophoblastic disease?
A group of rare tumors that involve abnormal growth of cells… starting in the cells that would normally develop into the placenta
___________ DNA stimulates placental development.
Paternal
What is the difference between complete and partial moles?
- Complete: diandric diploid (46, XY or XX), meaning the sperm contributed all of the genetic material
- Partial: diandric triploid (69, XXY), meaning two sperms fertilized one egg or one sperm fertilized one egg and then divided intra-egg
How will partial and complete moles appear on ultrasound?
Partial moles can have fetal parts and complete moles do not have parts and have a “snowstorm” appearance.
On gross exam, complete molar pregnancies have a ___________ appearance.
grape-like
20% of complete moles will develop into ______________.
gestational trophoblastic disease
Why do providers ask women who’ve recently had a complete molar pregnancy to take birth control?
Follow-up is done by monitoring hCG levels, so if a woman gets pregnant then the hCG levels will not be reliable.
How are complete molar pregnancies treated?
Curettage and (if hCG remains elevated) methotrexate
The key histologic finding in choriocarcinoma is _____________.
a biphasic tumor: mononuclear trophoblasts and multinuclear syncytiotrophoblasts
The most common site of choriocarcinoma metastasis is _____________.
the lungs
The placenta is divided into two sides, terminologically: ________________.
the fetal surface is where the cord attaches
What does IUFD stand for?
Intra-uterine fetal demise
Fetal vasculature enters the placenta in the _____________ spaces.
villous
The maternal blood enters the ___________ spaces.
intervillous (maTERnal = inTERvillous)
What can the attachment point of the umbilical cord tell you about the baby?
Most of the time, the umbilical cord attaches to the center of the placenta. In some cases, the cord can attach to the periphery. If it’s somewhat loosely/distantly attach –called velamentous –then there’s a greater chance that the child had hypoxic episodes due to repeated pressure occlusions.
There are two umbilical _________ but only one umbilical ____________.
arteries; vein
Increased _____________ increases risk of entanglement.
umbilical cord length
What is fetus papyraceus?
If a twin dies in a di/di, then the fetus that survives grows and presses onto the remnant sac of the other and can leave a fibrous impression.
Yellow blotches on a placenta can indicate _____________.
Listeria infection
Explain the extensive GP nomenclature system.
G = pregancies P = outcomes, denoted TPAL (term, preterm, abortion, living)
Example: G5P2032 is five pregnancies, two of which were term, zero were preterm, three were aborted, and two are living
What most commonly causes acute chorioamnionitis?
Group B Strep
Listeria leads to ___________ inflammation, whereas most other placental infections lead to ___________ inflammation.
acute; chronic
At 39 weeks’ gestation, about 15% of fetuses ___________.
have passed meconium
C-sections raise risk of ______________.
placenta accreta
Histologically, what two layers will be touching in placenta accreta?
The villi will abut the myometrium.
Hypertension and proteinuria after 20 weeks’ gestation indicate ___________.
pre-eclampsia
How common is pre-eclampsia?
It occurs in about 5% of U.S. pregnancies.
What are the sequelae of pre-eclampsia?
- 35% risk of stillbirth
- Preterm delivery
- Fetal hypoxia, neurologic injury
- Maternal DIC, stroke, HTN, and pulmonary edema
The only treatment for pre-eclampsia is ______________.
delivery
What is placental detachment called?
Placental abruption
What does the obstetric acronym SAB stand for?
Spontaneous Abortion
What’s the difference between symmetric and asymmetric intrauterine growth restriction?
- Symmetric: genetic etiology
* Asymmetric: non-genetic, physical malformation (such as oligohydramnios)
If a first trimester SAB has a cystic hygroma, what is the likely karyotype?
45, XO
Which trisomy increases the risk of omphalocele?
Edward’s and Patau’s
Neural tube defects can be detected by elevated levels of _____________.
AFP
What is the incidence of ectopic pregnancies?
1:150
In addition to hydropic villi, partial hydatidiform moles will have ______________.
fibrotic villi
Most complete moles arise from _____________.
one sperm that divides in an empty ovum
What is the incidence of complete hydatidiform moles?
1:1,500 pregnancies
Explain the utility of p57 staining.
p57 is maternally expressed, so it will be absent in complete moles.
There can be remnant _____________ in the umbilical cord.
GI epithelium (from when the GI tract bulged out into the cord)
The spiral arteries empty into the intervillous space after passing through the decidua _______________.
parietalis
What are signs of congenital HSV2 infection?
Same as in adults: temporal encephalitis, herpetic lesions
Compare and contrast the two types of villitis.
Infectious villitis: •Maternal and fetal illness • Early pregnancy •Less chance of recurrence •Very rare
Villitis of unknown etiology: •Less likely to have maternal and fetal illness • Late pregnancy •Greater chance of recurrence •More common
Placenta accreta is thought to form due to _____________.
failed decidual development
___________ is when the placenta invades the myometrium.
Placenta increta
Pre-eclampsia results from ________________.
impaired flow of blood from the spiral arteries to the intervillous space
What are symptoms of abruptio placentae?
- Rapid uterine contractions
- Vaginal bleeding
- Back pain
What causes acute abruption?
Rupture of villi due to ischemic injury
What is the incidence of Down syndrome?
1:700
