The gallbladder, like any fluid cavity, can be clearly observed on ultrasound examination. Failure to detect
the gallbladder ultrasonographically is rare, and usually in these cases a repeat
test (often involving a number of repetitions) on the following day will demonstrate
a gallbladder of normal size and location. However, if repeated ultrasound examinations
consistently fail to detect the gallbladder, other problems must be considered.
The main signs that should be checked for are those that are indicative of congenital
atresia (blockage) of the digestive tract, and excessively echogenic intestines. It is also necessary
to look for defects in the liver and intestinal structure, changes in the amount
of amniotic fluid, etc.
In cases in which the gallbladder cannot be detected even after repeated examinations,
it is advisable to examine the parents for carrier status of cystic fibrosis. It is also advisable to check for
a blockage in the bile ducts by analyzing the level of bile salts in the amniotic
fluid - this test is reliable, is coordinated through the genetic institute, and
is performed at this point in time in a special center in France. From the mothers
point of view the examination of the amniotic fluid is a regular test.