Ch. 28 The Fetal Gastrointestinal System Flashcards
The fetal gut develops at the end of the ___ menstrual week
5th (foregut, midgut, hindgut)
Seen as several parallel echogenic lines within the thorax
esophagus
Transvaginally., the fetal stomach can be seen as early ___ weeks but should be seen by ____ weeks.
8, 14
Diameter of small bowel is smaller than the colon and should not exceed ____
5mm
In early embryologic development, the origin of amniotic fluid is thought to result from an ____.
osmostic preocess.
Differentiating small bowel from the colon is achieved late in gestation, because the colon offers larger loops within the periphery of the abdomen and contains hypoechoic material representing ______.
meconium
fetal stool that is composed of fetal skin, hair, amniotic fluid, and bile
meconium
fetal biometric measurement of the abdomen made in the second and third trimesters; used in conjunction with other measurements to date the pregnancy and size the fetus
abdominal circumference
Abdominal circumference electronic calipers are placed around the entire outer perimeter of the abdomen. The abdominal diameter measurement is taken at the same level, with two perpendicular caliper sets. The formula for the abdominal diameter is AC = 1.57 × (____ + ____).
AD1+AD2
made in the axial view of the fetus and should include the fetal stomach, transverse thoracic spine, and intrahepatic portion of the umbilical vein and its junction with the left portal vein
abdominal circumference
an excessive amount of amniotic fluid for the gestational age
Polyhydramnios
Fetal kidneys begin to produce urine by ___ which comprises most of the amniotic fluid.
9 weeks
_________contributes greatly to the amount of amniotic fluid.
Fetal urine
What should be evaluated when polyhydramnios is detected?
fetal gastrointestinal tract
_______ is a substance that contains valuable proteins that are essential for normal fetal development. The fetus ingests amniotic fluid by swallowing. The fluid passes through the esophagus, into the stomach, and travels through the small bowel and into the colon, where absorption takes place. ________results when there is an obstruction or disturbance to the normal flow and absorption of amniotic fluid.
Amniotic fluid; Polyhydramnios
When polyhydramnios is detected, the sonographers should evaluate the fetal gastrointestinal tract carefully for signs of abnormalities, such as _____ or ________.
duodenal or esophageal atresia
congenital absence of part of the esophagus
esophageal atresia
congenital maldevelopment or absence of the duodenum
duodenal atresia
Condition associated with esophageal atresia 90% of the time
tracheoesophageal fistuala
an abnormal connection between the esophagus and the trachea
tracheoesophageal fistuala
acronym for associated anomalies; stands for vertebral anomalies, anal atresia, cardiac anomalies, tracheoesophageal fistula or esophageal atresia, renal anomalies, and limb anomalies
VACTERL
a fetus that is below the 10th percentile for gestational age (small for gestational age) and whose growth is impeded for some reason
intrauterine growth restriction
Sonographic Findings of ___________
1.Absent or small stomach
2.Polyhydramnios
3.Intrauterine growth restriction
Esophageal Atresia
Associated anomalies are often present in esophageal atresia and include duodenal atresia, _______ association, Down syndrome, ____________, and trisomy 18
VACTERL; intrauterine growth restriction
The congenital maldevelopment or absence of the proximal portion of the small bowel, the duodenum, is termed _______
duodenal atresia
Duodenal atresia classically presents sonographically as a dilated, fluid-filled anechoic stomach and an anechoic fluid-filled proximal duodenum, offering the ___________sign
“double bubble”
Duodenal atresia has a known association with
trisomy 21
associated anomalies of duodenal atresia include trisomy 21, _________, VACTERL association, ________, and cardiac anomalies.
esophageal atresia ;intrauterine growth restriction;
Sonographic Findings of ________
1.“Double bubble” sign
2.Polyhydramnios
3.Intrauterine growth restriction
Duodenal Atresia
What fetal lobe of the liver is larger and why?
left, because fetal circulation provides more oxygen to the left lobe in utero
Most common abnormality of the fetal liver
hepatomegaly (seen with intruterine infections, Rh incompatibility (fetal anemia), Beckwith-Wiedmann Syndrome
enlargement of the liver
Hepatomegaly
a growth disorder syndrome synonymous with enlargement of several organs, including the skull, tongue, and liver
Beckwith–Wiedemann syndrome
Enlargement of the fetal _____—_________—can accompany hepatomegaly and may be suggestive of intrauterine infections or Rh incompatibility with hydrops
spleen; splenomegaly
Fetal gallstones (cholelithiasis) and sludge within the gallbladder may be noted in utero, most often in the ______ trimester. Gallstones appear sonographically as echogenic foci in the right upper quadrant of the fetus that may or may not produce posterior shadowing
third; (*Gallstones persisting postnatally typically resolve postnatally)
the cystic dilatation of the common bile duct
choledochal cyst
inflammation of the bile ducts
cholangitis
the elevation of blood pressure within the portal venous system
portal hypertension
There are 4 different types of choledochal cyst but the most common is
cystic dilation of the CBD
Choledochal cysts can lead to ______, _______, pancreatitis, and liver failure
cholangitis,portal hypertension
The small intestine should not be ____ to or greater than that of fetal bone.
isoechoic
Echogenic bowel is linked to ________, _____, growth restriction, fetal demise, congenital infections such as cytomegalovirus, and gastrointestinal obstructions.
Down syndrome, cystic fibrosis
the transducer frequency plays a role in the diagnosis of echogenic bowel. One author suggests that if a ______ frequency transducer suggests echogenic bowel, that the sonographer should ______ the frequency to 5 MHz or less and decrease the overall gain.
higher; decrease
an inherited disorder in which mucus-secreting organs such as the lungs, pancreas, and other digestive organs produce thick and sticky secretions instead of normal secretions
cystic fibrosis
___________which causes a functional fetal bowel obstruction, is caused by the absence of nerves within the bowel wall
Hirschsprung disease
Hirschsprung disease is more common in _____, and there is a strong association with ________.The sonographic finding of dilated loops of bowel within the fetal abdomen is indicative of a fetal bowel obstruction.
males; trisomy 21
The sonographic finding of dilated loops of bowel within the fetal abdomen is indicative of a fetal bowel obstruction. These dilated loops of bowel should not exceed ____ mm in diameter or measure greater than ____ mm in length
7; 15
Obstruction of the fetal bowel most often occurs when there is a meconium plug causing the barrier, a condition referred to as _______
meconium plug syndrome
The most common type of colonic atresia that will lead to a bowel obstruction is ______
anorectal atresia
Anorectal atresia will most often lead to the visualization of a __________.
dilated fetal rectum
______this congenital maldevelopment of the rectum and anal opening causes dilation of the bowel.
anorectal atresia
Anorectal atresia may be linked with _________association and chromosomal abnormalities; thus, a thorough analysis of the fetus for other abnormalities is vital.
VACTERL
Two of the most common ventral abdominal wall defects are
gastroschisis, omphalocele
If the fetus has an abdominal wall defect (opening in the abdomen), then a ______ amount of AFP is allowed to pass into the maternal circulation.
greater
_____ levels of MSAFP are found in the presence of omphalocele and gastroschisis and thus can be used as a reliable screening test for the early detection of these and other abnormalities. Furthermore, it is important to note that MSAFP levels have been shown to be much higher in _______ than in omphalocele.
Elevated; gastroschisis
As a part of normal fetal development during the first trimester, the midgut herniates into the base of the umbilical cord; this is termed __________
physiologic bowel herniation
The intestines return to the abdominal cavity by the ____ week of gestation.
12th
the normal developmental stage when the midgut migrates into the base of the umbilical cord
physiologic bowel herniation
is the herniation of abdominal contents through a right-sided, periumbilical abdominal wall defect
Gastroschisis
Thought to be caused by a vascular incident occurring to either the right umbilical vein or omphalomesenteric vein
gastroschisis
Prognosis after surgery in a newborn is much better with this abdominal wall defect than those with omphalocele
gastroschisis
_______, unlike omphalocele, does ______ have a strong association with chromosomal abnormalities
Gastroschisis; not
With Gastroschisis recognizable loops of bowel are often noted outside of the abdomen floating in the amniotic fluid, and ______ Doppler should be used to demonstrate the relationship of the mass to the umbilical cord.
color
Clinical Findings of Gastroschisis
Elevated _________
MSAFP
Sonographic Findings of ________
1.Normal cord insertion
2.Periumbilical, right-sided mass
3.Recognizable loops of bowel outside the abdomen
4.Intrauterine growth restriction
Gastroschisis
an anterior abdominal wall defect where there is herniation of the fetal bowel and other abdominal organs into the base of the umbilical cord
omphalocele
An ________ is located within the midline of the abdomen. The ________ will insert into this mass. The entire content is contained and ______ by peritoneum and amnion.
omphalocele; umbilical cord; covered
______ is often noted within an omphalocele, as well as within the abdomen of the fetus.
Ascites
excessive fluid in the peritoneal cavity
Ascites
With an omphalocele a mass that contains liver has what kind of prognosis
poor
Clinical Findings of Omphalocele
Elevated _______
MSAFP
Sonographic Findings of ______
1.Midline abdominal mass at the base of the umbilical cord that contains bowel, the liver, and/or other abdominal organs
2.Abnormal cord insertion into the midline abdominal mass
3.Multiple associated anomalies
Omphalocele
Omphalocele has a more significant risk for _________and _________ than gastroschisis. Trisomy 18, trisomy 13, ______ syndrome, and Beckwith–Wiedemann syndrome have all been linked with omphaloceles.
heart defects; chromosomal anomalies; Turner
group of anomalies that include an omphalocele, along with ectopic cordis, cleft sternum, anterior diaphragmatic defect, and pericardial defects
Pentalogy of Cantrell
