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Echogenic Bowel |
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What is this and what is its significance? |
On ultrasound examination, the normal intestine appears gray/black, but an echogenic bowel
has a bolder appearance.
The echo returned from the ultrasound is more marked and the intestine appears whiter than the
other abdominal organs.
This is considered pathological when the intestinal echo (brightness) is greater than that from
the fetal bones.
It has been reported in about 1% of fetuses in the second trimester of pregnancy, especially
up to week 19, so that if it is present after this time it has a greater significance.
In most cases it has no significance and is a result of remnants of blood in the amniotic fluid
that have been swallowed by the fetus.
The iron in the swallowed blood coats the fetal intestine and causes this to appear echogenic on
ultrasonography. In these cases it will disappear or subside over time.
On the other hand, however, many fetuses have additional abnormalities that are associated with
the echogenic bowel.
In such cases, further investigation should be undertaken.
In disorders involving the blood flow to the fetus, intestinal edema may arise - in this case
there is an increased frequency of intrauterine growth retardation
and sometimes fetal death and abortion.
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The main causes of echogenic bowel are: |
- A blockage of the digestive tract because of a defect (which can usually be repaired) or
by the accumulation of viscous feces in the fetus's intestines (meconium ileus) as a result
of a disease such as cystic fibrosis.
It is advisable to test the parents for carrier status of this genetic disease.
- Intrauterine infection by a virus or other pathogen, e.g.
CMV (cytomegalovirus).
It is advisable to test the mother's blood for antibodies against teratogenic (causing fetal
damage) infective pathogens.
- Chromosome disorders in the fetus.
Various studies have shown that the risk for a chromosome disorder in the fetus in the case
of an extensive echogenic bowel that continues for a prolonged period is 14% - 16%.
In most cases where there is a chromosome disorder, additional defects are also present.
The risk of Down syndrome is especially high, and a number of studies have shown that this is
increased by a factor of nine in cases where an echogenic bowel is present.
However, other reports suggest that the risk is much lower if the echogenic bowel is an
isolated finding.
In the absence of large studies it is difficult to estimate the exact risk for a chromosome
disorder in the fetus.
- The onset of diffuse edema in the fetus - sometimes with an associated heart defect.
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What should be done if this is diagnosed? |
- The parents should be referred for genetic counseling in order to receive a thorough
explanation about its significance, and also to discuss whether further tests, particularly
amniocentesis, are advisable.
In cases of significant true echogenic bowel that continues for a prolonged period,
amniocentesis is indicated.
- It is recommended that the parents undergo a molecular test to check for carrier status
of cystic fibrosis.
It is important to test both parents, or at least the one whose test "coverage" is greater.
Women who have been tested in the past should be tested for the new mutations that have been
discovered since she was first tested.
- A thorough 3rd level ultrasound scan and further ultrasonic monitoring should be
undertaken in order to look for additional defects, to check whether there is intrauterine
growth retardation, and to ascertain whether or not the echogenic bowel has resolved.
- The mother should undergo a blood test to check her levels of antibodies against
teratogenic infective pathogens (TORCH organisms).
In the case of a suspected infection, the mother should be referred to her physician.
If there is a doubt as to whether the mother had an infection during pregnancy, amniocentesis
should be performed during or after the 21st week to test for fetal infection.
- Echocardiography should be performed between the 22nd and the 24th week of gestation.
- If all the above causes have been ruled out and the intestine is still excessively
echogenic, it is advisable to refer the parents to a multidisciplinary clinic in a hospital
for professional counseling by a geneticist, a pediatric surgeon, an expert in ultrasound
examinations and a neonatologist, in order to collate all the data and discuss the various
possibilities and courses of treatment that are available, etc.
The decisions taken will depend on the severity of the problem, the presence of additional
findings, etc.
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