Flashcards in Placental Pathology Deck (70):
The ____ layer of the trophectoderm remodels the endometrium to form the intervillous space.
outer syncytial layer
The ____ layer of the trophectoderm propagates to form villous structures.
inner mononuclear cytotrophoblast layer
Spontaneous abortion or miscarriage occurs due to ____
usually chromosomal anomalies or genetic mutation but also diabetes, endocrine abnormality, physical defect
Substance around fetal vessels
3 membranous layers of placenta
amnion, chorion, decidua
___ membrane is continuous with fetal skin
amnion --> fetal derived
the functional unit of the placenta is the _____________ of the chorionic villi which serves as the interface for nutrient and gas exchange between the fetal and maternal circulations
Blastocyst implantation has three phases:
apposition, stable adhesion and invasion
he trophectoderm penetrates through the uterine epithelium and deep into the ________________such that the entire gestational sac is implanted within the endometrium.
decidualized endometrial stroma
T/F The early intervillous space formed from the lacunae in the trophoblast shell is initially bloodless
T --> Direct connections are made but remain blocked by trophoblast plugs within the arterie
full perfusion of the intervillous space occurs around ___ weeks gestation via ___
12 weeks via uterine spiral arteries
How does dissolution of vascular mural smooth muscle facilitate implantation?
dissolution of the vascular mural smooth muscle which reduces vasomotor reactivity and resistance.
Umbilical arteries arise from ______
internal iliac arteries
This layer of the placenta is an admixture of extravillous trophoblast and decidua containing the terminal portions of the maternal arteries and veins.
maternal surface of placental disc is covered by ____
the ___ membrane separates the fetal blood from the maternal blood; the “membrane” is composed of apposed portions of the fetal capillary and ______ that are highly attenuated with cytoplasmic organelles and nuclei pushed to the side.
vasculosyncytial // villous trophoblast
T/F a dizygous gestation will always have two chorions and amnions.
Chorionicity in monozygous twins depends on:
timing of the division of the zygote.
Division within the first 72 hours after fertilization results in:
two separate embryos with their own chorion and amnion.
Division between 4-8 days, after development of the chorion ,results in:
a single chorionic disc but two amnionic sacs (monochorionic diamnionic )
Division after 8 days ,following development of the chorion and amnion , results in:
a single chorionic disc and single amnionic sac (monochorionic monoamnionic)
The presence of a monochorionic placenta indicates:
The presence of two chorions indicates:
nothing --> could be fused or not but either way is dizygous
___ is the only reliable method for confirming zygosity
molecular genetic testing
Chorionicity of conjoined twins by definition is :
T/F Gestations with increasing numbers of fetuses can have any combination of disc and membrane arrangements
2 pathways for placental infection
ascending from birth canal and hematogenous
____ route of infection is also referred to as “transplacental” indicating that there is infection of the placental disc
Ascending placental infection are often caused by ___ pathogens
bacterial (B strep, ecoli, fusobacterium), mycoplasma and rarely candida
Ascending placental infection results in inflammation of :
membranes (chorioamnionitis) and cord (funisitis)
____ is a frequent cause of preterm labor and delivery
ascending placental infection
Hematogenous placental infection are often caused by ___ pathogens
viral, toxoplasma, syphilis, and maternal bacterial sepsis
Hematogenous placental infection results in inflammation of :
____ is a frequent cause of fetal infection, growth restriction, and intrauterine fetal demise.
Hematogenous placental infection
T/F There is poor correlation of histological inflammation and clinical symptoms of chorioamnionitis in the mother
T/F . The stage and grade of chorioamnionitis are not reliably predictive of any particular clinical outcomes and are not necessarily reported as such.
In contrast to the maternal inflammatory response, severe fetal inflammation is predictive of _________ at term, has been associated with cerebral palsy, early onset fetal sepsis and clinical signs/symptoms in the mother.
fetal neutrophils infiltrate the umbilical vessels and wharton's jelly
maternal inflammatory cells infiltrate villi via intervillous space
T/F fetal inflammatory response has worse outcomes/sequelae
_______ is associated with acute neutrophilic inflammation with microabscess formation
Viral infections such as Cytomegalovirus can have increased numbers of plasma cells mixed with lymphocytes and histiocytes. The inflammation causes injury and loss of the surface trophoblast and subsequent _____ of the villi.
Prolonged inflammation of the villi can lead to:
loss of the fetal capillaries and scarring of the stroma
____ infection causes cellular enlargement and large, eosinophilic glassy nuclear inclusions as well as smalller basophilic cytoplasmic inclusions
The majority of cases of “villitis” have no associated infectious pathogen and are designated:
villitis of unknown etiology (VUE)
2 possible effects of vascular lesions of placenta
disrupt blood flow between uterus/placenta and placenta/fetus
T/F Umbilical cord knots can be asymptomatic or result in obstruction to flow of the fetal circulation
retroplacental hemorrhage signs
maternal pain, bleeding, uterine enlargement due to premature placental separation
____ is most common associated condition with retroplacental hemorrhage
compression of the ____ in plcaneta can result in severe acute hypoxia and fetal death.
underlying villous parenchyma
The trophoblast on the surface of the villi are supported by ______ in the intervillous space as opposed to the central portion of the villous or the stroma which is supported by the fetal villous vessels.
Interruptions of maternal blood flow, result in ischemic injury of the _____.
trophoblast --> In the acute phase of an infarct the fetal vessels may appear preserved. However, if the loss of surface trophoblast is severe enough the villous suffer further injury with eventual loss of the internal structure as well, resulting in avascular (non-functional) villi.
____ is a clinical syndrome of maternal hypertension, proteinuria, and edma associated with high morbidity and mortality of mother and fetus.
Preeclampsia --> superficial implantation of placenta and incomplete remodeling of uterine spiral arteries
Preeclampsia is sometimes referred to as ____
toxemia of pregnancy
hemolysis, elevated liver enzymes and low platelets --> associated with preeclampsia
Preeclampsia is more common in ___ women
primiparous --> pregnant for the first time
_______ occurs in approximately half of cases affected by preeclampsia
Atherosis of spiral arteries
_________ tumors identified in the placenta include neuroblastoma, hepatoblastoma, sacrococcygeal teratoma, and leukemia.
________identified in the placenta include melanoma, leukemia/lymphoma, breast carcinoma, and lung carcinoma.
2 types of gestational trophoblastic disease
hydatidiform mole, gestational trophoblastic tumors
tumor like masses in otherwise normal placentas
vascular lesion, leiomyoma, hepatic/adrenal adenoma
T/F chorangioma are benign
T --> proliferation of small vessels and surrounding stroma; the trophoblast on the overlying surface can be hyperplastic .
2 mechanisms for complete molar pregnancy
gestational sac is only composed of paternal DNA --> 1. 1 sperm fertilizes empty ovum with duplication of xsome, 2. 2 sperm fertalize empty ovum
features of complete molar pregnancy
lack fetal parts, and characterized by trophoblast hyperplasia and stromal edema
Partial molar pregnancy mechanism
2 sperm fertilize normal ovum = triploid --> fetal parts with variable hyperplasia and stroma
Which molar pregnancy type has higher risk of trophoblastic tumor and which has lower?
complete = higher, partial = lower
Trophoblastic hyperplasia results in what clinical marker?
4 kinds of trophoblast derived tumors
invasive mole, choriocarcinoma, placental site trophoblastic tumor, epithelial trophoblastic tumor
T/F choriocarcinoma risk is hgihest in middle maternal age 20-40
F --> at age extremes