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
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.
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.
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.
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.
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
- 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.
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.