Pregnancy & Placental Pathology Flashcards
Fetal side of the placenta
Maternal side of the placenta
Umbilical vein brings blood (in/out) the placenta.
Umbilical arteries bring blood (in/out) the placenta.
Umbilical vein brings blood OUT of the placenta.
Umbilical arteries bring blood IN the placenta.
What is the histological composition of the Umbilical Cord?
2 arteries, 1 vein
Wharton’s jelly (gelatinous polysaccharide)
What are some examples of cord abnormalities? (4)
- Marginal insertion (edge of disk)
- Velamentous insertion (into membranes)
- Knots
- Pseudoknots
Cord entanglement
Funisitis (cord inflammation)
Blood & neutrophils
Ascending infections of amniotic fluid
What are the different types of placental membranes? (3)
- Amnion
- Chorion laeve
- Decidua capsularis
What type of staining is this?
Meconium staining
Yellow-brown pigment laden MΦ
Chorioamnionitis
Maternal neutrophils
From decidua to surface
What is the composition of the placental disk? (3)
- Amnion
- Chorionic plate & chorion frondosum
- Chorion frondosum = chorionic villi
- Fetal vessels
What is the composition of the trophoblast?
- Syncytiotrophoblast
- Cytotrophoblast
- Intermediate trophoblast
Oligohydramnios
What does fetal vasculopathy look like on histology?
Hypertrophic vessels
Thrombosed vessels
Not a lot of oxygen exchange
What does the maternal decidua look like on histology?
Decidua basalis
Large decidual cells
Smattering of lymphocytes (triggers labor)
Not pathologic
Placental Abruption
Maternal surface
Arteries of mother’s uterine wall
Impeded blood flow –> clot
What are the 4 types of implantation abnormalities?
- Previa - over cervix
- Accreta - into the myometrium
- Increta - deeper into the myometrium
- Percreta - through the uterine wall
What does the villous parenchyma look like on histology?
- Chorionic villi
-
Fetal stem vessels & villous capillaries
- Fetal blood
- Intervillous space (maternal blood)
What does distal villous hypoplasia look like on histology?
- Terminal villi don’t have capillaires (avascular)
- Leads to intrauterine growth restriction, placental insufficiency
- Parenchymal Infarctions
- Death of villi due to lack of oxygen
- Ischemic necrosis
- No remodeling (just death)
- Small & peripheral infarction less clinically significant than one that is large & central
Infarction
What are the two types of placental infection?
-
Ascending
- From GI/GU tract
- Bacterial
-
Hematogenous
- Via maternal blood, into placenta
- Viral (infection visible in villi)
Placental Infection
Fetal response
Maternal response
-
Fetal response
- Leukocytes from fetal blood vessels into cord & chorionic plate
- **Maternal response **
- Leukocytes from decidual vessels into membranes & from intervillous space into villi
**Ectopic Pregnancy **
Definition
- Implantation of fertilized ovum anywhere other than the uterine cavity (1% of all pregnancies)
- 90% tubal
- Ovaries
- Peritoneal surfaces of the abdomen
Ectopic Pregnancy
Risk Factors
- Anything that obstructs the tubes
- Chronic inflammation (salpingitis, PID)
- Tubal ligation
Ectopic Pregnancy
Early stages
Eventually
- Early stages of pregnancy unremarkable
- ß-hCG increases normally
- Menstruation stops
- Eventually
- Embryo may die due to inadequate attachment
- Placental invasion causes rupture w/ massive hemorrhage & shock
What are the 3 types of Gestational Trophoblastic Disease?
- Hydatiform mole (complete & partial)
- Invasive mole
- Choriocarcinoma
Molar Pregnancy
Definition
- Arises from 2 sperm fertilizing an empty (complete mole) or normal (partial mole) egg
- Chorionic villi swollen, edematous, grape-like
- Produces ß-hCG
Complete Mole vs. Partial Mole
- Karyotype
- Villous edema
- Trophoblast proliferation
- Atypia
- Serum hCG
- Behavior
- p57 staining
- Fetus
Invasive Moles
Definition
- 10% of gestational trophoblastic disease
- Complete mole w/ invasive behavior
- No metastatic potential
Choriocarcinoma
Definition
- 2-3% of gestational trophoblastic diseae
- Very aggressive, malignant neoplasm
- 50% occur in the setting of complete mole, others after SAB or normal pregnancy
- Highly chemosensitive
Pre-eclampsia/eclampsia
Definition
- HTN + edema + proteinuria in 3rd trimester
- 5-10% of all pregnancies
- More common in older women
-
w/ seizures = eclampsia
- Can be accompanied by DIC & multisystem organ failure
- Treated symptomatically, but need to deliver baby
Pre-eclampsia/eclampsia
Histology
- Inadequate maternal blood flow to the placenta due to **incomplete remodeling of the spiral arteries **
- Instead of muscular layer, trophoblast lining
- _Trophoblasts don’t contract _
- Wide open blood flow
What are 3 types of placental malignancy?
-
Primary placental tumors
- Hydatidiform moles
- Choriocarcinoma
-
Metastatic disease from mother
- Melanoma
- Breast
- Others (rarely)
- *intervilli space*
-
Fetal tumors
- Neuroblastoma
- *villus capillaries*
