The Fetal Abdomen (lesson 19)

Question 1

What is pseudoascites?

Answer 1

Hypoechoic muscles in the abdomen

Question 2

What organs and structures develop from the embryonic foregut? (4)

Answer 2

Liver, gallblader, ducts, and pancreas

Question 3

At what week does an outgrowth develop on the caudal portion of the foregut?

Answer 3

4th wk

Question 4

When does gut herniation resolve?

Answer 4

By 13 wks

Question 5

When does bile secretion begin?

Answer 5

12th wk

Question 6

Does the gallbladder reach the anterior abdominal wall?

Answer 6

No, it does not

Question 7

The spleen is similar in echogenicity to what? And slightly less than what?

Answer 7

Similar to kidneys, less than liver

Question 8

What can echogenicity in the stomach indicate?

Answer 8

Can be seen in third-trimester placental abruption, and can represent swallowed blood or vernix

Question 9

What is meconium?

Answer 9

It is composed of materials the fetus ingests during gestation, and it is less echogenic than the bowel walls

Question 10

What are the two most common abdominal wall defects?

Answer 10

Omphalocele and gastroschisis

Question 11

What is the distinguishing feature of an umbilical hernia vs an omphalocele?

Answer 11

The position of cord insertion

Question 12

What can cause elevated AFP levels in the amniotic fluid or maternal serum?

Answer 12

Abdominal wall malformations

Question 13

Abdominal wall malformations DECREASE or INCREASE AFP?

Answer 13

Increase

Question 14

What are the two types of omphalocele? Describe each type.

Answer 14

These are when the bowel does not migrate back into the abdomen and remains in the umbilical cord. Big OOMPH.

Type I - owing to a fusion failure of the lateral ectomesodermal folds

Type II - failure of the muscle, fascia, and skin to fuse

Question 15

What is the size range for an omphalocele?

Answer 15

2-10cm

Question 16

When there is an omphalocele present, where is it and what is it covered by?

Answer 16

Located centrally, and always covered by a membrane

Question 17

When can a sonographer definitively diagnose Omphalocele in the first tri-mester?

Answer 17

When the omphalocele is larger than the abdomen

Question 18

The presence of what two organs in the omphalocele is bad news?

Answer 18

Spleen or heart

Question 19

How large is gastrochisis?

Answer 19

2-4cm

Question 20

What substances can mum use to put baby at risk for gastrochisis?

Answer 20

Nicotine or cocaine

Question 21

Does gastrochisis cause a raise in AFP?

Answer 21

Yes, due to bowel direct contact with the amniotic fluid, doubles in comparison to omphalocele

Question 22

Does an omphalocele cause a rise in AFP?

Answer 22

Yes, but not as high as gastrochisis

Question 23

Diabetic mothers and macrosomic fetuses have what size of liver?

Answer 23

Large

Question 24

How do liver calcifications occur in the fetsuses?

Answer 24

Intrauterine infections, especially TORCH infections, and toxoplasmosis and herpes

Question 25

If the sonographer thinks a fetus has gallstones, what else could it be?

Answer 25

Tumefactive sludge or thickened bile

Question 26

Is esophageal atresia male or female predominant?

Answer 26

Male

Question 27

What can cause an absence of stomach fluid?

Answer 27

Oligiohydramnios and stress of nonimmune hydrops

Question 28

At what weeks should you be concerned for a consistently empty or small stomach?

Answer 28

18 wks

Question 29

What artery does the bowel twist around in midgut volvulus?

Answer 29

SMA

Question 30

What side does gastrochisis usually occur on?

Answer 30

Right side

Question 31

What is a symptom of midgut volvulus?

Answer 31

Bilious vomiting

Question 32

What sign is associated with midgut volvulus? (think dishwasher)

Answer 32

Whirlpool sign

Question 33

What is duodenal atresia?

Answer 33

The failure of the duodenum to change from a solid cord of tissue to a tube

Question 34

What are the 3 duodenal recanalization anomalies?

Answer 34

Duodenal diaphragm or web, results in stenosis Solid cord with atresia Segmental or partial absence of the duodenum

Question 35

Duodenal atresia is most commonly associated with what?

Answer 35

Trisomy 21

Question 36

When is echogenic bowel a concern?

Answer 36

When it is greater than the echogenicity of nearby fetal bones

Question 37

What is the most common echogenic mass in the fetal abdomen?

Answer 37

Echogenic bowel

Question 38

What are five differential diagnoses with increased bowel echogenicity?

Answer 38

- Congenital fetal infections (cytomegalovirus) - Chromosomal abnormalities such as triploidy and trisomy 21, 18, 13 - Mesenteric ischemia - Meconium ileus - Swallowed blood from intra-amniotic bleeding

Question 39

What is the membrane that omphaloceles are covered by?

Answer 39

Peritoneum/amnion