13. Placenta and Cord Flashcards
You can first start to see the placenta around __ weeks
8 weeks (focal thickening along the periphery of the gestational sac)
The placenta should be shaped like a disc around
12 weeks
Focal hypoechoic areas under the chorionic membrane (or within the placenta)
Venous lakes
Variant Placental Morphology
Two near equal sized lobes - connected by a thin strip.
Bilobed placenta has an increased risk of ____
Type 2 vasa previa (Vessel cross the internal os)
Port partiumhemorrhage from retained placental tissue
Velamentous insertion of the cord
Variant Placental Morphology
High risk of placental abruption and IUGR
Circumvallate Placenta
Placental thickness of < 1 cm (Too thin)
Placental insufficiency
Materanl HTN
Materanal DM
Trisomy 13
Trisomy 18
Toxemia of pregnancy
Placental thickness of > 4 cm (Too thick)
Fetal Hydrops, Maternal DM,
Severe Maternal Anemia
Congenital Fetal Cancer
Congenital Infection
Placental Abruption
This is a premature separation of the placenta from the myometrium.
Placental Abruption: — PAINFUL
“disruption of the retroplacental complex.”
Placental Abruption
anechoic or mixed echogenicity beneath the placenta (often extending beneath the chorion)
“disrupts” the retroplacental complex of blood vessels
Abruptio placenta
displace the retroplacental complex
Myometrial contration / Fibroid
This is a low implantation of the placenta that covers part of or all of the internal cervical os.
Placenta previa
Margin of the placenta = 2 cm of the internal cervical os
Low-lying placenta
Margin of the placenta extends to the edge of the internal cervical os
MArginal placenta previa
Covers the internal os
Complete placenta previa
centered over the internal os
Central placenta previa
This is an abnormal insertion of the placenta, INVADES the myometrium.
Placenta creta
Risk factors of placenta creta
C-section
placenta previa
advanced maternal age.
Placenta accreta
a “moth-eaten” or “Swiss cheese” appearance of the placenta,
thinning of the myometrium (<1 mm)
Most common form of placenta creta
Placenta Accreta
The villi attach to the myometrium, without invading.
Placenta Accreta
illi partially invade the myometrium
Placenta Increta
The really bad one. Villi penetrate through the myometrium or beyond the serosa. Sometimes there is invasion of the bladder or bowel.
Placenta Percreta
This is basically a hamartoma of the placenta, and is
the most common benign tumor of the placenta.
Placenta Chorioangioma
Placenta Chorioangioma
well- circumscribed hypoechoic masses near the cord insertion.
What is a diagnostic Placenta Chorioangioma finding?
Flow within the mass pulsating at the fetal heart rate
(they are perfused by the fetal circulation).
Placental Chorioangioma VS Placental Hematoma
Chrorioangioma has pulsating Doppler flow
Hematoma does NOT
what artery is missing in the two vessel cord?
LEft artery
When is the Two Vessel Cord common?
Twin pregnancies
Maternal DM
Chromosomal anomalies
This is the term for when the cord inserts into the fetal membranes outside the placental margin, and then has to travel back through the membranes to the placenta (between the amnion and the chorion).
Velamentous Cord insertion
Common in twins
In risk of IUGR
This is basically almost a velamentous insertion (cord is within 2 cm o f the placental margin). It’s also seen more in twin pregnancies.
Marginal Cord Insertion
Fetal vessels that cross (or almost cross) the internal cervical os
Vasa Previa
Two types of vasa previa
Type 1: Fetal vessels connect to a velamentous cord insertion within the main placental body
Type 2: Fetal vessels connect to a bilobed placenta or succenturiate lobe.
