Ultrasound chapter 61
Sonographic findings of an omphalocele are
-Central abdominal wall defect -Evisceration of bowel or liver and bowl into base of cord -Continuity of cord into omphalocele -Covered by membrane -Ascites -hydramnios 1/3
Sonographic appearance of gastroschisis?
-right paraumbilical defect -free floating bowel
The incidence of omphaloceles is roughly
1 in 4,000
Gastroschisis is not known to be genetically transmitted although the recurrence risk is at __%
3.5
Chromosomal anomalies occur in __% to __% of omphaloceles
35 to 60
Fusion of the killing begins during the ___ week of development and is completed by the ___ week
7th, 8th
Perinatal mortality with an omphalocele approaches ___ when more than one fetal abnormality exists
80%
Umbilication hernia of the bowel occurs during the ___ week of development
8th
During which weeks of development does the fetal bowel normally migrate into the umbilical cord from the abdominal cavity
8th to 12th
The membrane thay covers the omphalocele consists of the
Amnion and peritoneum
Gastroschisis is found more commonly in
Males
What may be seen with gastroschisis outside the abdominal cavity in the area of the cord
Multiple loops of bowel
The insertion is ___ for gastroschisis
Normal
Develops when there is a midline defect of the abdominal muscles, fascia, and skin that results in herniation of intra abdominal structures into the base of umbilical cord
Omphalocele
When the bowel loops fail to return to the abdomen, a bowel containing ___ occurs
Omphalocele
The three most common defects of abdominal wall in utero
Omphalocele, gastroschisis, and umbilical hernia
To differentiate between an omphalocele and gastroschisis look for:
Presence of membrane, gastroschisis doesn't have one, look at umbilical cord because the cord goes through omphalocele and gastroschisis is found to the right of cord, determine which organs are eviscerated, determine of bowel is normal in texture, and look for other anomalies because omphaloceles often occur with chromosomal abnormalities
___ ___ is always found in the herniation with gastroschisis
Small bowel
Gastroschisis is an opening in the layers of thr abdominal wall with Evisceration of the bowel and infrequently the ___ and rarely the ___
Stomach, liver
Gastroschisis is located where in relation to the cord
To the right of cord
When a chromosomal abnormality and other major anomalies predict no chance of survival the baby will usually be delivered how
Vaginally
A normal cord insertion suggests
Hernia
The normal embryologic herniation of bowel permits the development of ____ organs and allows necessary ____ rotation
Intra abdominal, bowel
Ascites is/isn't present with gastroschisis?
Is not
Omphaloceles are characterized into two types:
1. Those that contain liver within the sac 2. those that contain a variable amount of bowel without the liver
Occurrence of gastroschisis is
1.75 to 2.5 in 10,000
Without other anomalies the mortality rate is approximately __% with isolated omphalocele
10
The midgut usually returns into the abdominal cavity by the ___ week
11th
The sonographer is able to detect gastroschisis after __ weeks gestation
12
Gastroschisis has an incidence of
12 in 10,000
Intestines return to the abdominal cavity by the ___ week of gestation
12th
Gastroschisis defects are small (__-__) cm
2 to 4
When organomegaly and macroglossia are observed what syndrome is suspected
Beckwith Wiedemann
Liver omphaloceles may contain a ___
Bowel
To prevent bowel damage and contamination the baby is usally delivered how
C section
Fetuses that have an omphalocele that contains only bowel have a higher risk for what
Chromosomal abnormalities and other anomalies
Almost all infants that have an omphalocele will die when there is what else is present
Chromosomal or major heart defect
3 main characteristics of omphalocele
Covered by a membrane, herniation into the base of the cord, AFP levels are slightly elevated
By the end of the 5th week of development and embryo is a flat disk consisting of 3 layers:
Ectoderm, mesoderm, endoderm
Other types of abdominal ventral wall defects include:
Ectopia cordia, bladder and coacal exstrophy, amniotic band syndrome, limb body wall complex
The prognosis for an infant with uncomplicated gastroschisis is
Excellent
AFP levels are significantly higher in gastroschisis due to
Exposed bowel
In the 6th week a process called ___ occurs to help the embryo transform itself into a cylindrical shape
Folding
Peri umbilical defect that nearly always located to the right of the umbilicus
Gastroschisis