13. Placenta and Cord

Question 1

You can first start to see the placenta around __ weeks

Answer 1

8 weeks (focal thickening along the periphery of the gestational sac)

Question 2

The placenta should be shaped like a disc around

Answer 2

12 weeks

Question 3

Focal hypoechoic areas under the chorionic membrane (or within the placenta)

Answer 3

Venous lakes

Question 4

Variant Placental Morphology

Two near equal sized lobes - connected by a thin strip.

Answer 4

Question 5

Bilobed placenta has an increased risk of ____

Answer 5

Type 2 vasa previa (Vessel cross the internal os)
Port partiumhemorrhage from retained placental tissue
Velamentous insertion of the cord

Question 6

Variant Placental Morphology

High risk of placental abruption and IUGR

Answer 6

Circumvallate Placenta

Question 7

Placental thickness of < 1 cm (Too thin)

Answer 7

Placental insufficiency
Materanl HTN
Materanal DM
Trisomy 13
Trisomy 18
Toxemia of pregnancy

Question 8

Placental thickness of > 4 cm (Too thick)

Answer 8

Fetal Hydrops, Maternal DM,
Severe Maternal Anemia
Congenital Fetal Cancer
Congenital Infection
Placental Abruption

Question 9

This is a premature separation of the placenta from the myometrium.

Answer 9

Placental Abruption: — PAINFUL

Question 10

“disruption of the retroplacental complex.”

Answer 10

Placental Abruption

Question 11

Answer 11

anechoic or mixed echogenicity beneath the placenta (often extending beneath the chorion)

Question 12

“disrupts” the retroplacental complex of blood vessels

Answer 12

Abruptio placenta

Question 13

displace the retroplacental complex

Answer 13

Myometrial contration / Fibroid

Question 14

This is a low implantation of the placenta that covers part of or all of the internal cervical os.

Answer 14

Placenta previa

Question 15

Margin of the placenta = 2 cm of the internal cervical os

Answer 15

Low-lying placenta

Question 16

Margin of the placenta extends to the edge of the internal cervical os

Answer 16

MArginal placenta previa

Question 17

Covers the internal os

Answer 17

Complete placenta previa

Question 18

centered over the internal os

Answer 18

Central placenta previa

Question 19

This is an abnormal insertion of the placenta, INVADES the myometrium.

Answer 19

Placenta creta

Question 20

Risk factors of placenta creta

Answer 20

C-section
placenta previa
advanced maternal age.

Question 21

Answer 21

Placenta accreta

a “moth-eaten” or “Swiss cheese” appearance of the placenta,

thinning of the myometrium (<1 mm)

Question 22

Most common form of placenta creta

Answer 22

Placenta Accreta

Question 23

The villi attach to the myometrium, without invading.

Answer 23

Placenta Accreta

Question 24

illi partially invade the myometrium

Answer 24

Placenta Increta

Question 25

The really bad one. Villi penetrate through the myometrium or beyond the serosa. Sometimes there is invasion of the bladder or bowel.

Answer 25

Placenta Percreta

Question 26

This is basically a hamartoma of the placenta, and is

the most common benign tumor of the placenta.

Answer 26

Placenta Chorioangioma

Question 27

Answer 27

Placenta Chorioangioma

well- circumscribed hypoechoic masses near the cord insertion.

Question 28

What is a diagnostic Placenta Chorioangioma finding?

Answer 28

Flow within the mass pulsating at the fetal heart rate

(they are perfused by the fetal circulation).

Question 29

Placental Chorioangioma VS Placental Hematoma

Answer 29

Chrorioangioma has pulsating Doppler flow

Hematoma does NOT

Question 30

what artery is missing in the two vessel cord?

Answer 30

LEft artery

Question 31

When is the Two Vessel Cord common?

Answer 31

Twin pregnancies
Maternal DM
Chromosomal anomalies

Question 32

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).

Answer 32

Velamentous Cord insertion

Common in twins

In risk of IUGR

Question 33

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.

Answer 33

Marginal Cord Insertion

Question 34

Fetal vessels that cross (or almost cross) the internal cervical os

Answer 34

Vasa Previa

Question 35

Two types of vasa previa

Answer 35

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.